In Chrome Settings - Notifications, are any sites allowed to show notifications? If so, remove or block them. Also, disable Chrome running background apps when closed. That is also in Settings.
Try mp3tag to view all the .mp3 in that folder. You may be able to see if a couple of the files have something unusual in one of the tags. There are many tag fields... or even tag versions.
Is the Win 11 box getting a valid IP from the Comcast gateway? If so, try manually adding a primary DNS 8.8.8.8 and secondary 8.8.4.4 in the Ethernet (Network 2) connection. Test again to troubleshoot.
If it's happening to all your PCs, perhaps it related to a 3rd party app you install. It doesn't happen to any of mine or the any of the 100+ I manage daily.
I also received this update on two of my PCs. However, Event Viewer still shows event 1801... Updated certs are available but have not yet been applied.