The issue has been resolved with a tech visit. Shout out to Marc, who did a great job getting things sorted out. Turns out the problem was what I thought it was all along: no tv signal at all. I had no problems with internet or phone the whole time. Marc said that (I'm paraphrasing here) the video signal from the ONT got turned off remotely (??). He had to call in and get someone to switch it back on.
VZ phone support is not worth much when it comes to cablecard. To humour them (and move things along), I swapped out my 6-tuner Ceton card for my older 4-tuner card and showed that I still had the same problem. No amount of re-pairing the cablecard worked because nothing was going to the card. The tuner diagnostics showed -50 or so for the signal. Now, I have return this cablecard they sent me and hopefully billing doesn't turn into a nightmare.
Anyways, I wanted to update this post in case someone else runs into this problem. BTW, I am in a MDU set-up.
