Free version works better than paid version.

My HP Laser printer is broadcast from my Linux computer using Avahi and this same printer is also broadcast directly from the printer itself using Air Print. Printer Pro Light works fine with both of these sources but the Printer Pro (paid for) app only works with Air Print, not Avahi. So in my case Printer Pro Light works better than Printer Pro. Printer Pro is also a higher version than Printer Pro Light which may be causing the problem.

rrrssssss about Printer Pro by Readdle