Inbound SSH connections from source IP of the Xfi router

I have been a longtime customer and set up port forwarding on my Xfi router to send SSH requests to my WAN IP on to my Linux server I run internally. On that Linux server, I have a local firewall and am tracking where SSH requests are coming from as a point of curiosity and most are what one would expect, IPs from Russia, Europe and other places knocking on the door of my machine. The thing I did NOT expect to see was a large number of SSH requests with a source IP of my WAN IP address on the router! This made me wonder if someone had compromised my router and was attempting to use it to launch attacks on devices inside my network. Can anyone at Xfinity address this concern? Is there a way I can know that my router is not compromised? Is there a way to determine the source of the inbound SSH connections that appear to be coming from that IP?