Do people feel like there was an AI change between late beta and release as far as the AI attacking defensive walls?
I basically rebuilt my base in release in the same place as during beta, and before all the roaming doinks would circle around my walls to the fort gates before they started attacking.
I gave up on my current game for now because they just kept attacking the wall wherever they'd impact it, and slowly work their way down my walls rather than pathing to the open gate. It wasn't an insurmountable problem, just really really tedious. The resource cost and time for where I'm at in game basically means I'd be repairing my walls full time. Not to mention having to walk my units all the way around my base to kill them since they will just keep attacking until the cows come home.
Now that I think about it, I have occasionally noticed my own guys occasionally fail to respond to a move order to enter the base my its only gate. And some behavior where the AI preferentially started attacking my walls instead of my gate despite being right next to it. Yet then again, the scripted AI attacks had no problems walking in to my base.
A while back, but after release, some of your walls would spontaneously fall apart if you walled off your base entirely. That was changed so that if the AI couldn't path into your base through a gate, they'd attack the nearest wall (which are all made out of tissue paper). If you have a gate but the AI can't "see" it, even after a CTRL-SHIFT-F11 then it could just be a bugged bit of map that you might be able to get around by laying down your own pathing - but that's overkill. Some mods that remove clutter make certain preset buildings completely inaccessible. I think the one I had trouble with was... hmm, either "reduce stones and some other foliage" or "clean and speed". I recently upgraded my PC so I don't use either of them anymore, though I still use the reduced textures mod, which is just great.
If you don't have any mods installed like that, maybe do a SHIFT-F12 and try rebuilding the mesh. You can also see the pathing from that menu, but personally I don't know enough about it to tell you how to edit it. I HAVE done it in the past, but I've also caused myself some spectacular problems with the editor. I wonder whether you'll find that there's a pathing track that leads directly to the wall being attacked, which your base is cutting off access to the other side.
Worst case, replace the wall that's being attacked with another gate. At least you'll know to defend it, and the gates have more HP (I use a mod to increase this further anyway).
To someone's point about crashes, FWIW I went from constant crashes with a i5-3750K 16GB GTX970 to almost no crashes with a Ryzen 3600 32GB 5700XT build, while using much the same mod list on both PCs. I suspect the RAM has made the most difference.