HELP! Crystal Cavern: Pixie Acres stuck

I tried to switch horses so I could move the pillar at the beginning of the Picie Acres Crystal Cavern quest, but the game glitched and wouldn't do anything, so I closed the software (switch) and restarted it. Now it's stuck on "The door is blocking your way. Find a way to open it." When I ride around the cavern, all of the obstacles have been dealt with already, no crystals to destroy, and no pegasus to be found. How do I fix this?!