After spending the best part of Christmas Eve trying to set up AirPrint on my HP p1102w printer on my new network, I began suspecting that something on my new router might be blocking. After long googling I found the suggestion that AirPrint might work if I set it up on a guest network.  In fact, this worked.  Now my next question is: which is the different setting preventing AirPrint to function on my main network? When I set up my printer, it can see the main network but the main network doesn't seem to see my printer. 

I also found the suggestion that enabling IGMP would solve the problem but unfortunately there is no such option on my AXE5400 settings, as far as I can tell.