After RO my barns and pastures are a mess and so I'm shuffling a lot of horses.
I clicked on my 'Auctions/Captures' barn and selected 'has rider' to move those into one of my pastures (empty pasture, 100 free spots). I click on submit, it says 'moved' on the top, but all horses are still in the barn, the pasture is empty.
I tried it 3 more times, each time with doing other things in between (bravery testing, etc) - it still doesn't work.
When I click on a horse individually I can move it with no issue.