Greetings @BinkyBoo,
Welcome to HP Forums and Thanks for the post.
I understand that you are unable to connect your printer to the new router. Don't worry, I will be glad to help.
Have you tried to setup the printer through USB and then converting it to wireless?
All HP printers work only on 2.4Ghz networks and not on 5Ghz networks.
You can press the keys on the printer repeatedly to get the numbers entered on the printer.
Alternately, you can setup the printer with the USB connection and then convert it to wireless.
Please refer to this guided tool for assistance in converting USB to wireless.
Let me know if this helped.
If the information I've provided was helpful,
Please give us some reinforcement by clicking the "Accepted Solution" and "Kudos" buttons,
That’ll help us and others see that we’ve got the answers!
Good Luck.
Chimney_83
I am an HP Employee