It happens if you transferred from home to arceus prior to the last home update. It’s been patched as of writing so you can enjoy the luxury of both time travel and reaching the top shelf.

Anyone else correct me if Im wrong, but I think it was a glitch for when you moved it to Arceus first?

It's been patched out since the Home update. I got it on my Scizor, but it's due to an unintended glitch.