I have a tier 5 horse that had the jump ability and the blue ability where your horse can run the next tier, I have 600 Pearl's and spent 200 which is 20 tries on getting a new skill for the horse and I was aiming for the green skill which is sprinting while running, idk if it's just bad rng but out of 20 tries???? I got every other ability it had to offer except the green one, is it possible to have the green ability and the blue ability together on the same horse or is it only possible for a horse to only have one of the two skills? All the blue skill does is increase the running tier and the green is to boost the speed while running, I think it shouldn't be a problem but if it interferes with each other then I can see why it would only have one of the two skills which increases the speed.

that not bug, but someone can call it bug. in BDO sometimes got problem like you. and 1 more thing you must know sir, 2 skill 1horse will not stack.