I have noticed this occurring quite randomly, and for a week or two, so I sadly don't know what type of info is needed.

I have noticed that no matter if I buy, or breed a horse, there is a 70% chance they get sent to a random barn that has an open spot, instead of my first barn (That I also named with A: so that it appears on the top of my lists).

(Excluding captures, because I can select the barn, lol)

I have tried moving my barn compounds arounds, moving the incoming barn around, moving another barn in front of it, but this still seems to be occurring, and I have no idea what else to do.

I have the same issue on my accounts as well as when transferring them to a new barn, they go to any open barn instead of the first one

I put a fix in, see if you still have this problem.