I had the same experience with an old HP 1200n, which was an otherwise rock solid printer, but I couldn’t get it to play nicely with AirPrint for love or money. I tried every permutation of CUPS + strange, half-baked drivers I found somewhere. I bought a little commercial print server that listed it as compatible but printed everything in 1/2 size. It was worth the price of a new printer to have one that Just Worked with my family’s devices.