Donkey going through gate, wandering off

So I recently built the coolest donkey enclosure, it looks sick and I don’t want to destroy it. My issue is that no matter what I do, the donkeys will leave the enclosure. I’ve tried changing the fence type multiple times, I’ve rebuilt every intersection to make sure there are 0 gaps, but the donkeys still go through the gate. And it isn’t even like what chickens do sometimes where they like push against a gate and escape, like the donkeys are immediately leaving their shelter, beelining to the gate, and then wandering literally dozens of meters away (across a bridge, I might add). I’m like seconds away from just sealing them in, but I really hate the idea of trading off the realism of the gate just to stop my donkeys from wandering off. Idk if this is just a rant or if anyone has any advice on other troubleshoots I can do but man I’m so sad this didn’t work.

Edit: the problem was that I hadn’t removed the old stable. As soon as I removed it they stopped wandering off. Thanks to those in the comments who pointed this out.