As of the last week my connection stability with spectator on and in 10v10 has been borderline unplayable. I'm playing from New Zealand but have over 1500 hours in this game, with most of it being in spectator on lobbies or ranked.
Its even gotten to a point as of today where there's a desync between which team I'm on in the pre-game lobby, and I can't even see myself change team. Yet my friends have told me they can see me switch teams.
I've tried flushing my own DNS, using mobile hotspot (which is with another ISP), reinstalling the game, playing at different times, resetting firewall permissions. I would say in a good 70% of my games lately the lag has been worth surrendering over. This is an issue that has only appeared in the last 7 days or so.
I'd like to continue playing by simply switching spectator off, but most lobbies in multiplayer don't work that way, and my experience without spectator is just as unplayable. This has never been an issue for me in the past and the game has been plenty playable for almost all of the hours I've put into it.