Oh, sorry to hear that! I'll look into it right away. Did you happen to do anything else between leaving and coming back to the dungeon?
Hello! I did have something weird like that happen, now that you mention it. I was in another dungeon, and I noticed that I had a master key already and was able to sequence break the dungeon that way, and the master key in there couldn't be picked up. I didn't think about taking that master key specifically and using it back on the other dungeon I got stuck on. That might let me continue on. Thank you!