Hi, shortly after solving Puzzle 28 I was trying to submit the solution to Meta Puzzle Mission 2 but on the first try (after failing once without spaces) I got:
You’ve already solved this challenge.
You can only solve each challenge once. Play again after the next challenge drops in the Rapyd developer community.
In a new private window it accepted the solution without trouble. So I guess there might be a bug there.
Edit: found the issue also previously reported in another thread.