Sorry for the ignorant question but does spectating take up a spot ingame?
I just played an 8v8 game where someone spectated throughout the entire match. For the 15 or so minutes the match was going on it was always 8v7. There’s also been scenarios I’ve come across where I try to join a game that’s seemingly 13/14 or 15/16 but keep getting a “Game is full” message despite refreshing the server list (Though that might not even be related).