How to fifix facebook messenger chat head bug on Lenovo Vibe X?

So I have a lenovo s960 and the chat heads keep bugging up… They work for a while… Sometimes days, sometimes minutes… But ultimately at a time they freeze up completely… Nothing seems to work but restarting my phone… I know that I can just turn them off, but that beats the whole purpose of the messenger… Cause, if I have to leave an app to reply, I can do that with the facebook app… Please help to fix this…

The bottom one is messenger opened again, and is working fine (until it bugs up too) and the top one is just stuck there… Can't do nothing about it…How to fifix facebook messenger chat head bug on Lenovo Vibe X