Is the xb8 modem limited to 1gb on port 4- April 2023?

Despite everyone knows the public info that says port 4 is up to 2.5gbs, xfinity has a major issue on its hands. 

I’ve been calling xfinity for 6 weeks now.  I have multi gig service, xb8 modem, but all 4x ports on the modem are limited to 1gb when I login into the admin portal and look under LAN connection to test each port.  I had a tech test the physical line connection, run a new coax line to the house, swap the modem to another xb8.  

The issue is somehow on the backend configuration where xfinity is limiting the connection to 1gb but no one can fix it.  Xfinity tech support is 5-6 hours on the phone multiple times and they are lost.  Please help.