Mobile Printing & Cloud Printing

I have a MFP M283cdw USB'ed to a Windows 11 PC. I can print to the printer from the PC, and also from iPads via wifi just fine. I set it up for HP ePrint to print remotely and that was working too for about a month, although some embedded images do not print and it takes about 10 minutes to print.

About a week ago, sending to the magic email address (qmmxxxxxx@hpeprint.com) stopped working when attempting to print PDF files generated the same way that worked previously. I get a response from the ePrint server that the server received the email, and ePrint facility is still set 'on' on the printer setup and the magic email address didn't change. I also saw somewhere that nothing other than the email address can be on the 'To' line and that some text has to be on the Subject line so I made sure that was true. And the body of the message was blank but with the PDF attachment.

And then in another office with the same model printer, I set up the ePrint process the same way (HP Smart) and that one works now.

It's almost like ePrint stops working a month after initially setting up the facility like I have to buy the service, but I don't see anywhere to buy the service.

I also saw someplace that HP stopped supporting ePrint long ago and now we should use Print Anywhere or something? Or is that just for mobile devices and ePrint is still supported for desktops?

As an aside, I was trying to register the printer as my printer under my HP login ID but I see nowhere to do that. How can I do this?