As per title.
I've tried everything, WPS, USB, WiFi, uninstall, reinstall and it still fails to connect.
I've had to leave my 2.4Ghz WiFi on on my HH6 and connect to that to able to use the printer.
The printer has the latest drivers and firmware installed.
I have a mixture of devices, both 2.4Ghz and 5Ghz and everyone of them connected first time (even the British Gas Smart Meter).
Info and update, if anyone else has problems with connecting an HP printer, use EWS (Embedded Web Services), it will connect through that.