It's a crock, forget I posted it.
In the end, what I still do is to delete all the sub accounts, turn off the machine, go for a walk to calm down, and then re-install the sub accounts. It works fine then, until it doesn't. Which sometimes can be as long as a month, or as short as a few minutes.
I wish I had never started this post.
It is a vast improvement, so much so that I made this post, but it ain't the perfect fix.
