HP Photosmart 6520 no longer functions as scanner since update to Catalina

My MacBook Air running Catalina (latest update 10.15.7) is having a hissy fit about the HP Photosmart software I installed 3 years ago, saying that it is malware.

I uninstalled the software as per the Apple support page, and deleted all printers from my printer list. I re-connected the 6520 without reinstalling the HP software and tried to get the scanner to work using, presumably, Apple's own drivers. It is an AirPrint printer.

The printer function works, but I could not connect to the scanner using Image Capture. It simply says that there is an error communicating with the device (sorry, but I didn't note the error number).

So I followed an HP help thread, and reinstalled the minimum software (HP EasyStart). The Mac warnings (eg HPDM.framework will damage your computer. Report malware to Apple to protect other users) started again. On the Image Capture app, I get a "Waiting for scanner..." messaging, but the scanner doesn't connect.

So, what is going on? If Apple bans the HP drivers/software, it would be lovely if they could put something that works in its place....

Help...