It’s almost every time I go into a match. As soon as I hit the lobby there’s about a 50% chance I can no longer see my missions in the drop down menu. After a match, nearly 100% of the time.
On the up side, it looks like maybe the “performance” tab on the match summary screen might be fixed. It was bugged for at at least a year where some of the mission slots were filled with sensible nonsense.