diff --git a/src/components/middle/FloatingActionButtons.tsx b/src/components/middle/FloatingActionButtons.tsx
index dfcebcd2b..ccbbdde0a 100644
--- a/src/components/middle/FloatingActionButtons.tsx
+++ b/src/components/middle/FloatingActionButtons.tsx
@@ -26,6 +26,7 @@ type StateProps = {
   messageListType?: MessageListType;
   unreadCount?: number;
   unreadReactions?: number[];
+  unreadMentions?: number[];
   reactionsCount?: number;
   mentionsCount?: number;
 };
@@ -39,6 +40,7 @@ const FloatingActionButtons: FC<OwnProps & StateProps> = ({
   chatId,
   unreadCount,
   unreadReactions,
+  unreadMentions,
   reactionsCount,
   mentionsCount,
   withExtraShift,
@@ -66,6 +68,12 @@ const FloatingActionButtons: FC<OwnProps & StateProps> = ({
     }
   }, [chatId, fetchUnreadReactions, hasUnreadReactions]);
 
+  useEffect(() => {
+    if (hasUnreadMentions && chatId && !unreadMentions?.length) {
+      fetchUnreadMentions({ chatId });
+    }
+  }, [chatId, fetchUnreadMentions, hasUnreadMentions, unreadMentions?.length]);
+
   useEffect(() => {
     if (hasUnreadMentions && chatId) {
       fetchUnreadMentions({ chatId });
@@ -153,6 +161,7 @@ export default memo(withGlobal<OwnProps>(
       chatId,
       reactionsCount: shouldShowCount ? chat.unreadReactionsCount : undefined,
       unreadReactions: shouldShowCount ? chat.unreadReactions : undefined,
+      unreadMentions: shouldShowCount ? chat.unreadMentions : undefined,
       mentionsCount: shouldShowCount ? chat.unreadMentionsCount : undefined,
       unreadCount: shouldShowCount ? chat.unreadCount : undefined,
     };
diff --git a/src/global/actions/api/messages.ts b/src/global/actions/api/messages.ts
index d1be24525..9ac10129b 100644
--- a/src/global/actions/api/messages.ts
+++ b/src/global/actions/api/messages.ts
@@ -67,10 +67,12 @@ import {
 import {
   addChatMessagesById,
   addChats,
+  addUnreadMentions,
   addUsers,
   deleteSponsoredMessage,
   removeOutlyingList,
   removeRequestedMessageTranslation,
+  removeUnreadMentions,
   replaceSettings,
   replaceThreadParam,
   replaceUserStatuses,
@@ -1655,9 +1657,7 @@ async function fetchUnreadMentions<T extends GlobalState>(global: T, chatId: str
   global = addChatMessagesById(global, chat.id, byId);
   global = addUsers(global, buildCollectionByKey(users, 'id'));
   global = addChats(global, buildCollectionByKey(chats, 'id'));
-  global = updateChat(global, chatId, {
-    unreadMentions: [...(chat.unreadMentions || []), ...ids],
-  });
+  global = addUnreadMentions(global, chatId, chat, ids);
 
   setGlobal(global);
 }
@@ -1668,18 +1668,7 @@ addActionHandler('markMentionsRead', (global, actions, payload): ActionReturnTyp
   const chat = selectCurrentChat(global, tabId);
   if (!chat) return;
 
-  const currentUnreadMentions = chat.unreadMentions || [];
-
-  const unreadMentions = currentUnreadMentions.filter((id) => !messageIds.includes(id));
-  const removedCount = currentUnreadMentions.length - unreadMentions.length;
-
-  global = updateChat(global, chat.id, {
-    ...(chat.unreadMentionsCount && {
-      unreadMentionsCount: Math.max(chat.unreadMentionsCount - removedCount, 0) || undefined,
-    }),
-    unreadMentions,
-  });
-
+  global = removeUnreadMentions(global, chat.id, chat, messageIds, true);
   setGlobal(global);
 
   actions.markMessagesRead({ messageIds, tabId });
diff --git a/src/global/actions/apiUpdaters/chats.ts b/src/global/actions/apiUpdaters/chats.ts
index 24ad5debd..acaab23d6 100644
--- a/src/global/actions/apiUpdaters/chats.ts
+++ b/src/global/actions/apiUpdaters/chats.ts
@@ -12,8 +12,10 @@ import {
   addActionHandler, getGlobal, setGlobal,
 } from '../../index';
 import {
+  addUnreadMentions,
   deleteChatMessages,
   leaveChat,
+  removeUnreadMentions,
   replaceThreadParam,
   updateChat,
   updateChatFullInfo,
@@ -177,13 +179,10 @@ addActionHandler('apiUpdate', (global, actions, update): ActionReturnType => {
 
       global = updateChat(global, update.chatId, {
         unreadCount: chat.unreadCount ? chat.unreadCount + 1 : 1,
-        ...(hasMention && { unreadMentionsCount: (chat.unreadMentionsCount || 0) + 1 }),
       });
 
       if (hasMention) {
-        global = updateChat(global, update.chatId, {
-          unreadMentions: [...(chat.unreadMentions || []), update.message.id!],
-        });
+        global = addUnreadMentions(global, update.chatId, chat, [update.message.id!], true);
       }
 
       const topic = chat.isForum ? selectTopicFromMessage(global, message as ApiMessage) : undefined;
@@ -220,10 +219,7 @@ addActionHandler('apiUpdate', (global, actions, update): ActionReturnType => {
         }
 
         if (!messageUpdate.hasUnreadMention && chat?.unreadMentionsCount) {
-          global = updateChat(global, chatId, {
-            unreadMentionsCount: Math.max(chat.unreadMentionsCount - 1, 0) || undefined,
-            unreadMentions: chat.unreadMentions?.filter((i) => i !== id),
-          });
+          global = removeUnreadMentions(global, chatId, chat, [id], true);
         }
       });
 
diff --git a/src/global/reducers/chats.ts b/src/global/reducers/chats.ts
index 38e705f0d..a0b1e6e65 100644
--- a/src/global/reducers/chats.ts
+++ b/src/global/reducers/chats.ts
@@ -96,6 +96,47 @@ export function replaceChats<T extends GlobalState>(global: T, newById: Record<s
   };
 }
 
+export function addUnreadMentions<T extends GlobalState>(
+  global: T, chatId: string, chat: ApiChat, ids: number[], shouldUpdateCount: boolean = false,
+): T {
+  const prevChatUnreadMentions = (chat.unreadMentions || []);
+  const updatedUnreadMentions = unique([...prevChatUnreadMentions, ...ids]).sort((a, b) => b - a);
+  global = updateChat(global, chatId, {
+    unreadMentions: updatedUnreadMentions,
+  });
+
+  if (shouldUpdateCount) {
+    const updatedUnreadMentionsCount = (chat.unreadMentionsCount || 0)
+    + Math.max(0, updatedUnreadMentions.length - prevChatUnreadMentions.length);
+
+    global = updateChat(global, chatId, {
+      unreadMentionsCount: updatedUnreadMentionsCount,
+    });
+  }
+  return global;
+}
+
+export function removeUnreadMentions<T extends GlobalState>(
+  global: T, chatId: string, chat: ApiChat, ids: number[], shouldUpdateCount: boolean = false,
+): T {
+  const prevChatUnreadMentions = (chat.unreadMentions || []);
+  const updatedUnreadMentions = prevChatUnreadMentions?.filter((id) => !ids.includes(id));
+
+  global = updateChat(global, chatId, {
+    unreadMentions: updatedUnreadMentions,
+  });
+
+  if (shouldUpdateCount && chat.unreadMentionsCount) {
+    const removedCount = prevChatUnreadMentions.length - updatedUnreadMentions.length;
+    const updatedUnreadMentionsCount = Math.max(chat.unreadMentionsCount - removedCount, 0) || undefined;
+
+    global = updateChat(global, chatId, {
+      unreadMentionsCount: updatedUnreadMentionsCount,
+    });
+  }
+  return global;
+}
+
 export function updateChat<T extends GlobalState>(
   global: T, chatId: string, chatUpdate: Partial<ApiChat>, photo?: ApiPhoto,
   noOmitUnreadReactionCount = false,