That's what I've tried to do every time there's a new release - update to the caught-up stable version before the beta upgrade. I haven't figured out the detail

That's what I've tried to do every time there's a new release - update to the caught-up stable version before the beta upgrade. I haven't figured out the details of how to make that happen after a year or so of attempts now. I've turned off the automatic updates now, so at least I won't accidentally get upgraded past the stable release this time.