After clearing a compound, a friend left. I was still in the compound. When he left the fireteam, the entire compound respawned (making for some fast work on my end to survive when a guy was RIGHT in front of me). As I was clearing the area, came across a prompt to silent-kill a baddie where a body was. So either he was invisible or the already dead guy gave me the prompt.

Video of the second issue:
https://t.co/SOlWADQqOr?amp=1