Windows 10 pro as a terminal server stopped working correctly. how to fix?

Question

Windows

Hello.
There is a computer with Windows 10 pro, as a server with a program for retail, on which rdp wrapper is installed, 8 accounts (in the "Remote Desktop Users" group). On the accounts, the workplace of the seller, accountant and merchandiser, forwarding of receipt printers, and one fiscal registrar are set up. All this worked until the windows update (it was forced to update, despite the suspended update for 30 days), which happened on the night of September 15-16. After this update, the rdp wrapper crashed, which I fixed without any problems through reinstallation; all the printers flew off, when connected via RDP, they simply did not exist, the printers partially worked after setting up the rdp shortcut (unchecked "printers", saved, connected, disconnected, ticked "printers", saved, connected), but not in all workplaces; the fiscal still didn't work, even directly, its own utility sees it, but can't do anything (print checks, reports, etc.).
As I later found out from familiar admins at a state enterprise, they also had the same problem after the update, which was solved by rolling back the last update, but in my case, the rollback only made it worse. After the rollback, the choice of accounts on the welcome window disappeared on the server, the "secure login" turned on - it asks to press "CTRL + ALT + DELETE to unlock"; all users via RDP received the "Shutdown" button, which they did not have, because of which they began to cut down the server; printers did not work, in some cases the printer is in the print window, but when sent for printing, the document appears in the print queue, and disappears after a few seconds, printing does not occur.
What was done:
Removing all updates and fixes to the state before September 15 - did not help.
Reinstalling printer drivers did not help.
The accountant works on the server through a separate account, it was not in the selection of accounts, corrected the situation by adding the account to the "Users" group, after which the account appeared in the selection in the welcome window.
Removed "Safe Login", now you can easily select accounts from the available ones and log into them.
Actually, what to do with it ?, since the rollback should have returned everything as it was, but in this case it broke even more. Reinstalling the system is not an option (only if nothing can be done with this system), since it will be difficult to restore the work of all cash desks, and at the moment the cash desks are working, goods are released, but they cannot print receipts.
As an option, I just don’t know if it will work or not, make a flash drive with win 10 pro edition 20H2, and roll it in update mode, in theory, this should roll back the entire system while saving all settings and programs.
If you have any ideas please let me know!

Answer 1

For the future. Do not use in sales any version other than LTSC or Win Server. Because the updates themselves are not installed there))
Yes, try to roll the update from the flash drive. Maybe a ride