Printing Errors or Lights & Stuck Print Jobs

A recurring false paper jam error is preventing me from scanning documents. All printing functions are working properly, and I am occasionally able to scan successfully through various tactics (power on/off, hard reset, etc.), but the false paper jam error always comes back in short order and prevents scanning again. 

I have tried all the fixes I have come across or could think of, including all the steps in the document HP LaserJet Pro, Ultra Printers - Paper Jam Error. I have checked all the paper pathways to make sure they are clear, of even small bits of paper, and clean. I have also used the printer's Restore Default command to reset the printer to its factory settings, and used macOS's Reset Printing System function in System Settings \ Printers & Scanners. The printer is plugged directly into a wall outlet. The printer's firmware is up to date. 

I bought this printer in 2018. I had not tried to add the printer to my HP profile till just now, and the 'Add a product to my profile' process does not recognize my printer, even though I double-checked that I am using the right serial number and model no./product code. Maybe that is a hint that my printer is considered elderly beyond hope. But the printer sees only light use, and its performance, except for this false error issue, has not degraded at all. It seems a real shame if its life has to end when its basic hardware capabilities are fully intact. What else can I try?