Sometimes when you close apps, some background services continue to run. Perhaps check your task manager and really look for any open background tasks related to antivirus.
Also, since you said it happens when you use the hotkeys, maybe you are triggering some macro? Do you have anything like AutoHotkey or Expanso installed? Are those hotkeys triggering something else that might be causing an infinite loop or a script or something?
Also looking at your screenshot: What about Focus-To-Do? Does that track your open windows? Try closing that.
You also have Adobe products installed. And those have some weird syncing background processes that eat up my network. I can’t imagine it causing display performance issues. But who knows. It’s Adobe. I’d try closing those too. Especially the “Genuine Software Integrity” one. <shivers>…
(Try closing one thing at a time if possible, to really find the culprit.)