Cannot get a hidden ability to pass down to offspring?

Question

This is extremely frustrating. I have a male Harvest Trevenant I got in a trade from Japan. I'm breeding it with a Harvest female I bred from a trevenant I caught in a whord, but none of the offspring are inheriting the HA. I've hatched over 40 eggs with 0 Phantump that have Harvest (though I got a shiny from it with the very first offspring, which is more terrible luck than good since it has frisk). I need to know what i'm doing wrong. Is the only way to get the hidden ability from the Japanese Trevenant to breed it with ditto? By the way, breeding a normal male with the HA female produced the same results.

Comments

According to Bulbapedia, female HA Pokemon can pass down the HA when bred with a male Pokemon in the same egg group. https://bulbapedia.bulbagarden.net/wiki/Ability So I guess you're just unlucky.

Answer 1

You're either
1. Unlucky
2. Doing you're breeding methods wrong*

*try breeding your male trevenant with harvest with a ditto. It worked for me(ditto plus my protean frogadier = protean froakies.)