Hi Bob,
thanks for your reaction.
I had and today have tried the solutions mentioned in the articles.
I again removed and installed the latest driver. The printer is on the latest firmware.
I tried another usb cable.
And disabled the usb selective suspend in the power options.
But issue persists.
The only difference with before the 24h2 upgrade is that after switching on the printer it prompts "waiting" in its display and then puts out the dummy pages (no print job given). It seems to me that usb connection goes to standby after some time if the printer is not online or goes itself to standby.