Untames horses are unable to be tamed in creative

In creative mode, when you feed a horse, it keeps eating and does not stop eating; therefore, you can't tame and ride it because it only begs and eats food. When you try to ride him, the horse just stands on its back legs, indicating it is untamed.

When I switched to survival, I fed another horse a stack of hay, and it ate them all, so it became tamed and I started riding it.