Local and remote access had been working for days. Out of nowhere, all remote access stopped working (HDHR OTA + Philo TVE). The error message said "Tuner Unreachable". Local viewing and recording worked fine. I couldn't find anything that had changed on my network. I restarted the server and all of a sudden remote access works again.
I'm happy that this worked, but are there preventative steps I can take in the future? I am running on a wired network using MoCA on a M2 Mac mini.