Ventura 13.3.1(a) occasionally hammers download speeds

I have a 2021 MBPro M1 with 32GB RAM.

For some reason, I've noticed my download speeds plummet to ~ 1-2 Mbps at times on my home Wifi, which prevents me from loading even basic web pages. I verified the home wifi works (another MB Air laptop download speeds are normal and has never had a problem).

This tends to happen when I have additional monitors (2) hooked up to that laptop. When I disconnect them, the download speeds return to normal. It also happens when certain applications run, which I now avoid as much as possible, but still need from time to time.

I've tried everything I can think of, including restarts, restarting my internet hub, removing the WiFi from System Settings | Network and re-adding it again. Still these sluggish download periods happen. Any ideas on how I can fix this?

Many thanks in advance.