Everyone on my server desynced at the same time. Using the auto-rejoin did not work (kept desyncing, disconnect/reconnect worked), but I did get this out of the desync report compare:
Thanks for the report.
I think it is fixed in 0.15.31. The problem was a player tried to put blueprint to his or her blueprint library that was already there but only locally. I am not sure why other players desynced, though.