Are they all in a series? There are no series listed either.
The latest update 1.4550 should show sermons not in a series, so if you have them all in series and latest update, could you refresh your database backup (there’s a button at the the top of the Church Admin page) and send it to me so I can investigate
The refreshing the DB was so you could send it to me for investigation.
Meanwhile, I’ve gone back to my site and seen sermon listing was a bit buggy for me (missing the last 10 sermons) – fixed that and just uploading now – suspect that will fix your issue too!