So I trained my horses and 3 of them are still there. When I try training them again it says they have already trained. They are Level 9, 8 and 5.

Do they all have riders assigned? Riders paid? Feeded?

And do you have links to the 3 horses please

Yes evrybody is assigned Everything is as it should be. And for whatever reason I tried it again and one trained.

Maybe because they are a schoolmaster in one event? Maybe change the discipline and try?

Did not work Thanks for suggesting!