LAN "internet" speeds under 100Mbps when they used to be near Gateway speed test levels.

I used to have blazing fast connections on my wired home devices that have gig port connections that were close to GW speeds.

However, I have noticed major slowness over this past two months.

Now when I do speed test my wired devices are getting under 100Mbps when they used to get 400-900 Mbps.

I tested connection on my home gigabit LAN using various freeware tools and my speeds are 400-900Mbps. 

My GW speed tests are over 1000Mbps.

I have reset my PC settings.  Swapped out the modem.  Swapped switches.  And no change.

Previous and new switch show the gig connection light (green s orange).  So I do not think it is my old and new switches.

So far my internet searches are turning up nothing.

I have two Win 10 PCs,  one Win 11, Xbox Series X and PS5 and they all get 80-97 Mbps!!!

I am at a loss.  Not sure what else to check.

I search the forums and see similar reported issues, but they are from old posts or posts with no updates.

Everyone I spoke to at Comcast via chat, phone, and at the store say the company does not throttle devices.

Yet this seems quite suspect :(

My wifi devices as of now seem fine and get better speeds even on the 2.4 band.

If I find something I will update my post.