While humming, you are unable to give the Lead Horse command to your mount.

lead horse
You are a bit too busy performing to do that.

Yet, I can remove tack from it, as well as mount and dismount it. Seriously, lead is no more complicated than grabbing the reins and guiding your horse. Would someone look into fixing this please?

Gidske

>Wouldn't surprise me if it's an issue related to the verb since it's also used for the Paladin lead ability.

I'm pretty sure the reason is that there's a list of verbs allowed while humming, and whoever wrote hum didn't think of horses when releasing it.