Can't Learn a Move It Can Learn

[Joshstrong494]

While on PKHex, my Garbordor, according to the application, is able to learn the move 'Spikes'. While selecting this move, PKHex claims it cannot be able to learn the move. So it's saying my Garbordor can learn 'Spikes', while at the same time, it can't learn the move. Everything else is legal, and this is for USUM if you need to know.

[Kaphotics]

Spikes is an egg move, and thus must be in the relearn moves section.

https://bulbapedia.bulbagarden.net/wiki/Garbodor_(Pokémon)#By_breeding

[centipeetle300]

my dodrio can't learn drill peck