Thanks go to Frank from Comcast. Technician #187. Ask for him by number. I don't know if he did anything in particular, or whether it was dumb luck, but... apparently I'm not the only one who's had this problem as of late.
Many, many people in the VA/DC/MD area have been having problems. For the past several months. Just like me.
Who knows. Who cares. It's up.
So again-- let us pray.