From bulbapedia...Yeah, been experimenting with breeding Issuians (as I like to keep regionals and side evolutions in Repeat Balls); Ball transfer is as it has always been, regional form breeding still requires Everstone to get non-natives from eggs, White stripe Basculin is not counted as a regional and breeds like the other Basculin forms, and, so far, I've been unable to get Hidden Abilities from non-regional fatherss into regional offspring: Justified male Kanto Arcanine x female Hissuian Arcanine (with Everstone) did not yield Rock Head Hissuian Growlithe. I was able to get HA Galarian Farfetch'd with a HA Kantonian Farfetch'd and a Ditto in Sword, so I'm not sure if this is new or standard breeding behaviour.
From Generation VI onward, if a female Pokémon, or any Pokémon bred with Ditto, has a Hidden Ability, there is a 60% chance that its offspring will have its Hidden Ability.
So Farfetch'd worked (and, from my experience, my Geodude, Corsola and Meowth) because you bred with a Ditto. Growlithe isnt working because the father doesnt pass it without Ditto