Printing to USB printer on another computer "Hold for Authorization"

[Wend44]

Description of the problem:

HP LaserJet Pro MFP M127fn USB printer defined (using HP Smart and HP Easy Start) and working on iMac Sonora 14.5. system name Mac2023. The printer is set up with printer sharing and all users permitted to print.

HP LaserJet Pro MFP M127fn @ Mac2023 defined on MacBook Pro Monterey 12.7.5. Printer definition was first set up (using HP Smart and HP Easy Start) with printer attached to MBP. When printer physically swapped here it worked. Then the remote printer definition is showing Online/Offline when powered on and off on iMac, indicating that the printer can be "seen" by the MBP system.

Both printer definitions are using version 1.7 of the drivers.

When I attempt to print from the MBP the print job is queued, but the job is shown as "Hold for Authentication."

The error log for the attempt to print is as follows:

E [18/May/2024:14:10:33 -0700] [Client 513] Returning IPP client-error-not-authorized for Create-Job (ipps://Mac2023.local.:631/printers/HP_LaserJet_Pro_MFP_M127fn) from [v1.fe80::1091:bb02:4cdd:f1c7+en0].
E [18/May/2024:14:10:39 -0700] [Client 514] Returning IPP client-error-not-authorized for Create-Job (ipps://Mac2023.local.:631/printers/HP_LaserJet_Pro_MFP_M127fn) from [v1.fe80::1091:bb02:4cdd:f1c7+en0].
E [18/May/2024:14:10:39 -0700] [Client 515] Unable to encrypt connection: Unable to establish a secure connection to host (-9806).

The only other fact that may be relevant is that when I originally set up the new iMac and tested remote printing from the MBP it was working fine. At that time the iMac was running Sonoma 14.4 and I used the printer definition on the MBP that I had been using with a previous iMac that was running High Sierra (!). I then updated the new iMac to Sonoma 14.5. I then completely reinstalled the printer definitions on both systems using the HP apps. I'm not sure, put the problem *may* have occurred after the MacOS upgrade.