My horses only accepted golden apple, they didn't eat wheat or other food from other mods.
My version is 1.20.1

They eat stuff from the o_horse_eats tag, so if other mods want to add their stuff to it they can.

Thanks for your assistance! Now I've solved it with a simple datapack. Thank you very much for such interesting mod created by you.

No worries, glad you found a fix :)