Why are my Unity-run games suddenly slow?,Why are my Unity-running games suddenly slow?

Over the past week, my games that run on the Unity game engine, including VRChat, Slime Rancher, Powerwash Simulator, and Subnautica, have started running slow. And this is ONLY on games that run on Unity. Other games like Satisfactory and Sea of Thieves run flawlessly at 60 fps and the highest graphics settings. I have a crazy fast computer with a Radeon RX 5500 XT graphics card and checked to make sure that everything was up-to-date. Did a virus scan and no issues found there. I cannot find the source of these Unity games running slow. Please help! I want to be able to play them again to my full satisfaction!