Dammit I should have written this right away: there are a bunch of version bumps in this release, especially compared to
v3.18.0, but even compared to the last beta.
Many of these will recompute indexes on the offset log, which will take a while, and during that time Patchwork will possibly look empty.
I wrote a post a while back explaining some of the mechanisms around indexing.
In particular for this beta I bumped...
Once these indexes are complete however, patchwork should be back to normal. You should have the progress bar at the top indicating the progress. If it does get stuck, please do tell, but this is a long-standing and hard to debug bug and actually one of the examples why patchwork won't be continued. A restart of patchwork often unblocks it.