Gastrodon with Earth Power legality

[futuresushi]

Hi!

I'm making a competitive team and I wanted to put Earth Power on Gastrodon, as it is tutorable in USUM. All the online dexes say it can get it, but it flags as illegal in PKHex 20191114 if I try. Any ideas what could be causing the issue? Are all the dexes wrong or is there some other factor I'm missing?

[Kaphotics]

Assuming it originated from Sun/Moon, it has to have a Handling Trainer set in order to obtain US/UM tutors (it has to leave the OT at least once, since the OT cannot obtain the tutors alone).

[futuresushi]

I had repeatedly set an Ultra Moon origin but it indeed had flipped back to Moon when I wasn't paying attention.

Thanks!