HP Printer and RAX120

I take it you have gone through the WiFi wizard setup and reading it can't be used whilst connected to a computer and wirelessly at the same time.

It was connected to USB but I unplugged rebooted PC and Printer and tried WIFI again and it still doesn't work.

Have you the manual for the printer?

I'm sure I can download it.  But I'll say this.  Only change I made to my network in a very long time was this router.  SSID and passwords all the same on this router vs my older one.  Which I still have.  Again its not to important I get this going. 

I'm actually an IT guy as well and its my nature to try and get this working but I don't print much.  And still can from my PC.  Just a nice added bonus to print Wifi when needed thats all.

https://support.hp.com/gb-en/product/hp-laserjet-pro-200-color-printer-m251-series/5097632

you need to run the setup wizard. I've linked the page above so you can check device drivers and obtain the manual.

So my router took a firmware update two days ago and I just noticed this morning that my printer is on WIFI again!  LOL

The result of "action at a distance".

I have the same Pinter Laserjet 200 and just got the AX12 and I have that same annoying problem. Everything is connected except my printer. It tells me that the Security passcode is incorrect. 

I also work in IT and this is super annoying. 

Ive done manual ip settings, reserved ips, and firmware updates etc. How did you fix the problem? Thanks

WIFI protected setup went through successfully on the Rounter both in Pin mode and puch button mode but also both ways displayed Failed to connect from the printer screen. For some reason this printer does not like this router!

Problem is definitely coming from the security types of the AX12, when I remove the security completely the printer connects, but I cant keep the network open so Im not sure what other option there is ( there isnt a firmware update available for the printer or router)