@Kitsap - Static route did the fix, but I had to do it a little differently than what you showed in your screenshots because my modem and router are separate devices. BUT - adding in a static route to the modem admin page going out the WAN interface fixed the issue.
After some asking around, it appears that XFINITY has a DOCSYS 3.1 modem script that runs once the modem attaches to the XFINITY ecosystem. It's pushed by XFINITY and nothing that you have control over. No idea why it's suddenly a problem, but it does explain a bit of the behavior.
In all cases, the static route was the fix and I can see everything now.
