This might not be relevant, but, I have previously made changes to print and point policy where, I needed to applied changes at the user level for it to work. This was necessary because I was working with a multi-level client environment. You can do it only as a test and revert if your not happy. With your specific problem, what raises questions, is the fact that this happens with non-admin users, and intermittent, where normally, by setting the policy to disable this disables the enhanced printer driver instalation security of 6. 1
But sounds, in your case, this is all being ignored and you are not able to connect or reconnect. After installed, Log off and on reconnect still able to access the printer. After confirming this, try to connect manually to a printer from a client. Also as a troubleshooting attempt, we can work with a different prespective, allowing the print and point restrictions and giving priveleges to 1 user, as a test to see if the problem is about this topic, or its something else we are mis understanding.
Not sure this is helpfull. I have had two user computers with this issue. One of the users the print spooler was being stopped by a corrupted printer driver. Every time the printer would go in to powersave mode it would in turn stop the spooler service. The other users printers would just disappear. Spooler still running and everything.
Found it was a Fujitsu scanner that was causing the problem. Unplug the scanner and haven\’t had a problem since. So your best bet is to uninstall every printer one by one until the spooler stops shutting down. Then you know which printer you need to find a different driver for or maybe just reinstall the driver for. Yes it is a lot of busy work but it took me a couple months to get to that step and that is how I finally found it. Good Luck!