Pro Clubs lag after goals + "unstable connection" every match

Every time I load into a Pro Clubs match, it says "Unstable connection" right at the start – even though I’m on wired fiber (1–10 ms ping). During the game, I get input delay and frame drops after every goal for about 2–3 minutes. I’m on PC with a GTX 1660 Super. Capping the game to 60 FPS makes it playable even after goals, but at 120 FPS the lag returns. My cutscenes are set to half frame rate – maybe switching to full frame rate would help? Anyone else dealing with this or found a real fix?