diff --git a/app/components/autocomplete/at_mention/at_mention.tsx b/app/components/autocomplete/at_mention/at_mention.tsx
index 8e0d4ede67..160d5c4455 100644
--- a/app/components/autocomplete/at_mention/at_mention.tsx
+++ b/app/components/autocomplete/at_mention/at_mention.tsx
@@ -17,6 +17,7 @@ import {useTheme} from '@context/theme';
 import DatabaseManager from '@database/manager';
 import {t} from '@i18n';
 import {queryAllUsers} from '@queries/servers/user';
+import {hasTrailingSpaces} from '@utils/helpers';
 import {makeStyleSheetFromTheme} from '@utils/theme';
 
 import type GroupModel from '@typings/database/models/servers/group';
@@ -85,13 +86,16 @@ const keyExtractor = (item: UserProfile) => {
     return item.id;
 };
 
-const filterLocalResults = (users: UserModel[], term: string) => {
-    return users.filter((u) =>
-        u.username.toLowerCase().startsWith(term) ||
-        u.nickname.toLowerCase().startsWith(term) ||
-        u.firstName.toLowerCase().startsWith(term) ||
-        u.lastName.toLowerCase().startsWith(term),
-    );
+const filterResults = (users: Array<UserModel | UserProfile>, term: string) => {
+    return users.filter((u) => {
+        const firstName = ('firstName' in u ? u.firstName : u.first_name).toLowerCase();
+        const lastName = ('lastName' in u ? u.lastName : u.last_name).toLowerCase();
+        const fullName = `${firstName} ${lastName}`;
+        return u.username.toLowerCase().includes(term) ||
+            u.nickname.toLowerCase().includes(term) ||
+            fullName.includes(term) ||
+            u.email.toLowerCase().includes(term);
+    });
 };
 
 const makeSections = (teamMembers: Array<UserProfile | UserModel>, usersInChannel: Array<UserProfile | UserModel>, usersOutOfChannel: Array<UserProfile | UserModel>, groups: GroupModel[], showSpecialMentions: boolean, isLocal = false, isSearch = false) => {
@@ -198,8 +202,7 @@ const getStyleFromTheme = makeStyleSheetFromTheme((theme) => {
     };
 });
 
-const emptyProfileList: UserProfile[] = [];
-const emptyModelList: UserModel[] = [];
+const emptyUserlList: Array<UserModel | UserProfile> = [];
 const emptySectionList: UserMentionSections = [];
 const emptyGroupList: GroupModel[] = [];
 
@@ -232,15 +235,15 @@ const AtMention = ({
     const style = getStyleFromTheme(theme);
 
     const [sections, setSections] = useState<UserMentionSections>(emptySectionList);
-    const [usersInChannel, setUsersInChannel] = useState<UserProfile[]>(emptyProfileList);
-    const [usersOutOfChannel, setUsersOutOfChannel] = useState<UserProfile[]>(emptyProfileList);
+    const [usersInChannel, setUsersInChannel] = useState<Array<UserProfile | UserModel>>(emptyUserlList);
+    const [usersOutOfChannel, setUsersOutOfChannel] = useState<Array<UserProfile | UserModel>>(emptyUserlList);
     const [groups, setGroups] = useState<GroupModel[]>(emptyGroupList);
     const [loading, setLoading] = useState(false);
     const [noResultsTerm, setNoResultsTerm] = useState<string|null>(null);
     const [localCursorPosition, setLocalCursorPosition] = useState(cursorPosition); // To avoid errors due to delay between value changes and cursor position changes.
     const [useLocal, setUseLocal] = useState(true);
     const [localUsers, setLocalUsers] = useState<UserModel[]>();
-    const [filteredLocalUsers, setFilteredLocalUsers] = useState(emptyModelList);
+    const [filteredLocalUsers, setFilteredLocalUsers] = useState(emptyUserlList);
 
     const runSearch = useMemo(() => debounce(async (sUrl: string, term: string, cId?: string) => {
         setLoading(true);
@@ -253,11 +256,19 @@ const AtMention = ({
                 fallbackUsers = await getAllUsers(sUrl);
                 setLocalUsers(fallbackUsers);
             }
-            const filteredUsers = filterLocalResults(fallbackUsers, term);
-            setFilteredLocalUsers(filteredUsers.length ? filteredUsers : emptyModelList);
+            const filteredUsers = filterResults(fallbackUsers, term);
+            setFilteredLocalUsers(filteredUsers.length ? filteredUsers : emptyUserlList);
         } else if (receivedUsers) {
-            setUsersInChannel(receivedUsers.users.length ? receivedUsers.users : emptyProfileList);
-            setUsersOutOfChannel(receivedUsers.out_of_channel?.length ? receivedUsers.out_of_channel : emptyProfileList);
+            if (hasTrailingSpaces(term)) {
+                const filteredReceivedUsers = filterResults(receivedUsers.users, term);
+                const filteredReceivedOutOfChannelUsers = filterResults(receivedUsers.out_of_channel || [], term);
+
+                setUsersInChannel(filteredReceivedUsers.length ? filteredReceivedUsers : emptyUserlList);
+                setUsersOutOfChannel(filteredReceivedOutOfChannelUsers.length ? filteredReceivedOutOfChannelUsers : emptyUserlList);
+            } else {
+                setUsersInChannel(receivedUsers.users.length ? receivedUsers.users : emptyUserlList);
+                setUsersOutOfChannel(receivedUsers.out_of_channel?.length ? receivedUsers.out_of_channel : emptyUserlList);
+            }
         }
 
         setLoading(false);
@@ -270,9 +281,9 @@ const AtMention = ({
 
     const matchTerm = getMatchTermForAtMention(value.substring(0, localCursorPosition), isSearch);
     const resetState = () => {
-        setUsersInChannel(emptyProfileList);
-        setUsersOutOfChannel(emptyProfileList);
-        setFilteredLocalUsers(emptyModelList);
+        setUsersInChannel(emptyUserlList);
+        setUsersOutOfChannel(emptyUserlList);
+        setFilteredLocalUsers(emptyUserlList);
         setSections(emptySectionList);
         runSearch.cancel();
     };
@@ -425,6 +436,10 @@ const AtMention = ({
         if (!loading && !nSections && noResultsTerm == null) {
             setNoResultsTerm(matchTerm);
         }
+
+        if (nSections && noResultsTerm) {
+            setNoResultsTerm(null);
+        }
         setSections(nSections ? newSections : emptySectionList);
         onShowingChange(Boolean(nSections));
     }, [!useLocal && usersInChannel, !useLocal && usersOutOfChannel, teamMembers, groups, loading, channelId, useLocal && filteredLocalUsers]);
diff --git a/app/components/autocomplete/channel_mention/channel_mention.tsx b/app/components/autocomplete/channel_mention/channel_mention.tsx
index 561ef7b55f..c8991bb338 100644
--- a/app/components/autocomplete/channel_mention/channel_mention.tsx
+++ b/app/components/autocomplete/channel_mention/channel_mention.tsx
@@ -17,6 +17,7 @@ import useDidUpdate from '@hooks/did_update';
 import {t} from '@i18n';
 import {queryAllChannelsForTeam} from '@queries/servers/channel';
 import {getCurrentTeamId} from '@queries/servers/system';
+import {hasTrailingSpaces} from '@utils/helpers';
 import {makeStyleSheetFromTheme} from '@utils/theme';
 
 import type ChannelModel from '@typings/database/models/servers/channel';
@@ -148,11 +149,12 @@ const makeSections = (channels: Array<Channel | ChannelModel>, myMembers: MyChan
     return newSections;
 };
 
-const filterLocalResults = (channels: ChannelModel[], term: string) => {
-    return channels.filter((c) =>
-        c.name.toLowerCase().startsWith(term) ||
-        c.displayName.toLowerCase().startsWith(term),
-    );
+const filterResults = (channels: Array<Channel | ChannelModel>, term: string) => {
+    return channels.filter((c) => {
+        const displayName = ('displayName' in c ? c.displayName : c.display_name).toLowerCase();
+        return c.name.toLowerCase().includes(term) ||
+            displayName.includes(term);
+    });
 };
 
 type Props = {
@@ -186,8 +188,7 @@ const getAllChannels = async (serverUrl: string) => {
 };
 
 const emptySections: Array<SectionListData<Channel>> = [];
-const emptyChannels: Channel[] = [];
-const emptyModelList: ChannelModel[] = [];
+const emptyChannels: Array<Channel | ChannelModel> = [];
 
 const ChannelMention = ({
     cursorPosition,
@@ -204,13 +205,13 @@ const ChannelMention = ({
     const style = getStyleFromTheme(theme);
 
     const [sections, setSections] = useState<Array<SectionListData<(Channel | ChannelModel)>>>(emptySections);
-    const [channels, setChannels] = useState<Channel[]>(emptyChannels);
+    const [channels, setChannels] = useState<Array<ChannelModel | Channel>>(emptyChannels);
     const [loading, setLoading] = useState(false);
     const [noResultsTerm, setNoResultsTerm] = useState<string|null>(null);
     const [localCursorPosition, setLocalCursorPosition] = useState(cursorPosition); // To avoid errors due to delay between value changes and cursor position changes.
     const [useLocal, setUseLocal] = useState(true);
     const [localChannels, setlocalChannels] = useState<ChannelModel[]>();
-    const [filteredLocalChannels, setFilteredLocalChannels] = useState(emptyModelList);
+    const [filteredLocalChannels, setFilteredLocalChannels] = useState(emptyChannels);
 
     const listStyle = useMemo(() =>
         [style.listView, {maxHeight: maxListHeight}]
@@ -227,17 +228,21 @@ const ChannelMention = ({
                 fallbackChannels = await getAllChannels(sUrl);
                 setlocalChannels(fallbackChannels);
             }
-            const filteredChannels = filterLocalResults(fallbackChannels, term);
-            setFilteredLocalChannels(filteredChannels.length ? filteredChannels : emptyModelList);
+            const filteredChannels = filterResults(fallbackChannels, term);
+            setFilteredLocalChannels(filteredChannels.length ? filteredChannels : emptyChannels);
         } else if (receivedChannels) {
-            setChannels(receivedChannels.length ? receivedChannels : emptyChannels);
+            let channelsToStore: Array<Channel | ChannelModel> = receivedChannels;
+            if (hasTrailingSpaces(term)) {
+                channelsToStore = filterResults(receivedChannels, term);
+            }
+            setChannels(channelsToStore.length ? channelsToStore : emptyChannels);
         }
         setLoading(false);
     }, 200), []);
 
     const matchTerm = getMatchTermForChannelMention(value.substring(0, localCursorPosition), isSearch);
     const resetState = () => {
-        setFilteredLocalChannels(emptyModelList);
+        setFilteredLocalChannels(emptyChannels);
         setChannels(emptyChannels);
         setSections(emptySections);
         runSearch.cancel();
diff --git a/app/utils/helpers.ts b/app/utils/helpers.ts
index 1a95d4c7df..f3cf904263 100644
--- a/app/utils/helpers.ts
+++ b/app/utils/helpers.ts
@@ -146,3 +146,7 @@ export const pluckUnique = (key: string) => (array: Array<{[key: string]: unknow
 export function bottomSheetSnapPoint(itemsCount: number, itemHeight: number, bottomInset = 0) {
     return ((itemsCount + Platform.select({android: 1, default: 0})) * itemHeight) + (bottomInset * 2.5);
 }
+
+export function hasTrailingSpaces(term: string) {
+    return term.length !== term.trimEnd().length;
+}