FYI, this post was made from my phone… apologies in advance for any oddities.
…so I am currently running Facebook app v188.8.131.52.30, as seen below;
In addition, I also have the Facebook Messenger App. Now, from the Messenger app, navigate to the settings as shown below(Green);
Then tap on “Chat heads”(Blue).
Turn Chat heads off by tapping on the button on the upper righthand corner (Green).
Feel free to leave a comment!