On iOS, this happens after every match together with the pre-season message. Now that they say they fixed the pre-season thing, maybe so this will. I’ll report after my match today.

My game friends disappear after matches, and they come back after closing the game and opening it back. They also disappear when I get our the game without closing it (it remains open in the background), and re-opening the game it reloads and the friends list is empty again. I don’t have FB so I don’t have anything to add on that part.