I’ve experienced it on highways, but as I noted in a parallel comment, if Tesla thinks Autosteer isn’t viable on non-highways, it’s odd that they make it available. They have no trouble identifying road type and using it to determine speed restrictions for autosteer, and no problem disabling autosteer if they can’t ID the lines.

Maybe the phantom breaking is so harsh in your car it’s giving you amnesia, because it’s a well-understood Tesla failure mode on the Teslamotors subreddit, TMC, and every other Tesla owner forum I’ve seen.