Naruna Hot Springs Dungeon Loot Drops outside of reachable area

When killing the final boss of the Naruna Hot Spring Dungeon whilst in the colourful ground phase the loot drops and you are immediately sent into a cutscene at teleported back to the original fighting area. This makes the loot unreachable. This happened to me on hard mode - I reran the dungeon and it didn’t drop the bonus chest, I assume due to it thinking I have already obtained it.

Really frustrating as these rewards are quite important for progression…

If a reward reset is possible so I can run the dungeon again and wait until it teleports back please let me know.