I tried updating two of my computers to 2004 again last Thursday, using the Malwarebytes 'work around' discussed in this and other threads...
One Via WU, and one with a MCT USB stick.
The updates took 2+ hours, but seemed to be successful. Both computers initially worked as expected...
However over the next 5 days, they had numerous problems as below:
Programmes/Apps not working. They just wouldn't start.
Windows error message Windows not responding on boot on the desktop, on both computers, having to boot 2 - 3 times to get Windows 2004 to run.
On one computer USB hardware no longer working. (works fine with 1909)
Note my Logitech wireless mouse and Logitech wireless keyboard connected via KVM hardware and USB worked fine.
Checking Device manager and forcing a USB driver update just said I had the most suitable/recent driver...
Google chrome stalling/freezing with waiting for cache message, had to reboot the computers to fix it.
Macrium Reflect stalling/freezing on start... Tried a repair of Macrium Reflect, seemed to fix it, for **one day**
Programmes/apps that run fine on 1909 getting memory access violations when starting on 2004..
Having to run Malware Bytes beta versions just to boot/run Windows 10 2004, seemed to work for the first two days then unable to open Malwarebytes from the Action Centre icon, Windows start menu, or from a desktop shortcut, even though Task Manager showed the Malwarebytes tray application was working.
I've rolled both computers back to 1909 again, and put Feature updates on a 30 day pause, to see if Microsoft releases any patches for 2004 before trying again.