Extreme Lag

Anyone had this over the past couple of months? My partner is on an M2 Mac mini and doesn’t get this. I’m on an M1 Ultra MacBook and will occasionally get a horrible latency - today it went to 15000, for example. And I’m plugged into the router. (I’ve tried wifi as well - no change). MacBook is closed and streaming to a less intensive dell monitor.

Just seems to be wow; when it happens YouTube, etc works fine.