I called Comcast. It was, as expected, a challenge to get the point across and try to convince them it wasn't an issue with my hardware or local area.

They finally escalated the ticket up to their higher support tier who can look at a national / regional issue and see if there's any over-arching problems on their side.

Not sure if/when I'll hear back from them but I'll keep this thread updated on the status as I get it.

I haven't opened anything with SE yet so if someone else wants to go that route?

(still having bad lag of this morning too so it's not gone away)