Hi getting the same error as previously mentioned, first time challenging the castle in a run and getting message saying I've already challenged. Happens over multiple play throughs

Been playing v0.9d for a bit now and I'm having trouble unlocking certain events such as the castle event. I know you need to collect pieces of the map to be able to unlock this event, found pieces by beating forest, deep forest and swamp bosses but can't seem to find the next piece of the map if ...