So, here's the thing. Been playing since season 6 and game ran smoothly most of the time. Season 20 drops, not only I had rough fps in menu, I couldn't really play something besides AI duels due to game only running in 20 fps on lowest graphics settings. Let alone playing in a group, I was kicked 15 seconds after the game start. This season, however, one issue was fixed - I could play solo. But anytime I connect to my friends/they connect to me I'm only having around 20-30fps in menu and then in drops to 15~ in any gamemode. It could've been an issue with latency, although it was busted soon after. Reinstalling the game or switching it to SSD, switching VSync or buffering didn't work.
My PC settings are:
Intel Core i5-7300HQ(goes up to 3.2GHz)
GeForce GTX 1050 4GB with latest drivers
16GB RAM (some HyperX stuff I suppose)
Also W10 21H2 if that matters