I’m blocked: no new level after the backwoods treasure.
As far as I can tell Backwoods Treasure (and in general, replayable levels) doesn’t unlock anything, but Rich Forager should unlock three new levels. Try replaying Rich Forager (ie. resubmit for a new random seed) and see what happens.
Please tell us if trotods tip helped you. If not we will investigate what caused the bug (I fear if it works it is just some strange internet-hickup that we can’t resolve).
Behavior like this has been known from Items which wouldn’t unlock despite the unlocking level being solved. Those could be resolved by replaying the level. This bug (should) has been fixed since a long time, but maybe a recent change in code produced this strange behavior. It is impossible to say at the moment.
Sorry for your inconvenience,
I have done again all the levels and it worked.