C7000 slow router speeds vs direct modem speeds

After several talks with Xfinity customer service and having a service tech come out to my house twice. It was determined that it's my router that needs correction. When I bypass the router to use it solely as a modem and wire directly to the PC, I get speeds of 240+ Mbps but when I use it as a router also, only get about 80 Mbps on the 5G band and about 30 on the 2.4 band. I have done a factory reset multiple times but it doesn't help.

Any help will greatly be appreciated.