I was going through my Level Up Reports and left for a few minutes. I came back and the Manage Your Horse dropdown has changed.

When I go to assign a new/higher level rider in the horses' dropdown, it makes me hire a new rider EVERY time regardless of whether one is available or not. This was just in the last ten minutes or so.

This is what I get, it doesn't tell me what level rider I need

This is the other problem, I have 2 horses that need a level 3 rider.

I have plenty of level 3 spots available

I'm having the same issue, I can't assign any horses to riders. It's only letting me hire new riders.

Should be fixed now, thanks!