Is there still an issue connecting Mac OS Catalina 10.15.7 to HP printers?

Open >System Preferences>Software Update

Update: HP Printer Software 5.1 should now be becoming available through Software Update to fix this issue.

(2220 UTC 23 October 2020)

If you still have an issue, and listed as AirPrint printer, delete the existing printer in

> System Preferences> Printers & Scanners, and add it again, select AirPrint.

Connect an AirPrint printer to a Wi-Fi network - Apple Support.

https://support.apple.com/en-us/HT201900

about AirPrint

https://support.apple.com/en-us/HT201311

you can also try reset print system if necessary:

If you can't print from your Mac or iOS device - Apple Support

https://support.apple.com/en-us/HT203343

You have to check Software Update and HP. HP revoked all of their old certificates which identified there software as valid. Once you get an update for your printer, you will have to remove the printer and add it back.

Which HP printer? I have no issues with my 6520 printer

My printer is an old model Laserjet 1010 which worked perfectly until the October update. Now it seems I have to chuck it in the bin and buy a new one. Throw away society gone mad IMHO