Hey NipqiN,
Welcome to Apple Support Communities.
We understand that you are having an issue with Facebook Messenger app on your MacBook.
Are you experiencing similar issues with other messages/chats app on the MacBook? This information will help isolate the issue.
Let's see if the app works as expected in safe mode. Safe mode can help determine whether an issue is caused by software that loads as the Mac starts up. For steps on booting into safe mode, click here: How to use safe mode on your Mac.
If it happens in safe mode, we recommend contacting Facebook Messenger app developer's support. Since the issue is isolated with Messenger, they should be able to further assist you. If you need help with locating their support, click here: How to contact an app developer .
Take Care.