Remove the HP Smart App or HP Update helper from your computer. These apps are designed to push silent firmware updates. Troubleshooting: Firmware Downgrade Fails
How to Downgrade HP OfficeJet Pro 8620 Firmware: A Complete Guide hp officejet pro 8620 firmware downgrade new
If you are looking for a downgrade, you already know why. HP’s infamous feature acts like a bouncer at a nightclub. It scans your ink cartridges. If they aren't HP-branded (or if they are older, "remanufactured" chips), the printer refuses to print. It turns your $200 printer into a paperweight. Remove the HP Smart App or HP Update