v3 onion services require a "live" consensus to publish or fetch
If the Tor v3 onion client, or Tor v3 onion service, do not have a "live" consensus (i.e. one where "valid-until" hasn't elapsed), then they will choose not to even attempt to fetch or publish v3 onion descriptors:
Jan 10 11:32:24.364 [warn] No live consensus so we can't get the responsible hidden service directories.
This bug got exposed today because the network went several rounds without a consensus due to the ongoing issues of #33018 (closed) and #33072, and thus Tor clients and Tor onion services ended up with a consensus that still worked (it was made within the past 24 hours), but was no longer considered "live".
So normal Tor circuits (using exit relays) still worked, and v2 onion services still worked, but v3 onion services stopped working for that time period -- services wouldn't publish descriptors, and clients wouldn't fetch them.
The fix imo is that we need to make v3 onion services work under the same time assumptions as the other parts of Tor -- if you have a usable consensus, then use it.