Anyone, please?

hi - I recently upgraded my motherboard and CPU to Ryzen 9 5900x. Everything works well except that the game freezes the first two seconds when I enter an online game with other players. When I play online with AI the game runs extremely fast on 60FPS (crazy fast it feels like 1000FPS). I tried other renderers and that didn't fix it. Skirmish works without issues. Could you please help? It used to run well with my previous Intel CPU.