reminds me that I had an issue with oban a while back, see Oban_jobs keeps old jobs
For some reason a migration hadn’t properly applied and now jobs wouldn’t run. The most notable part of it, was that old jobs weren’t removed, so I had a whole bunch with state ‘completed’, ‘cancelled’ and ‘discarded’, while those should be removed.
Federation worked partly, but retries didn’t happen. It took me much longer to realise this, though, so I’m not sure if it’s the same problem as you are having.
In my case, the database was missing a table oban_peers. I forced the migration to run again, although in a somewhat hacky way.