Game lag causing computer lag?

I have noticed over the past few weeks when I encounter lag spikes in the game my Mac also experiences lag. Task bar will stutter opening, websites will take longer to load. Switching windows slows to a crawl. I’ve had to turn graphic settings to 1 and turn off other settings. Everything was fine before all the pre patching for the xpac.

Is this more than just lag? Is there a memory leak or something making things much worse?

I just purchased the xpac and was hoping maybe things would smooth out but playing in the new zone is impossible when the lag starts.

Late 2019 intel. Maxed memory and ssd.