HP AirPrint Problems - HP Printer Support
- Check the compatibility of Air Print app to ensure that the mobile device and the printer that you use support this feature
- Restart your mobile device and printer to check if the errors resolve
- The internet connection that you use must be secure and active and hence we always recommend to switch over to an alternate network connection
Double check to make sure that the AirPrint feature is enabled and active on both your mobile device and printer.
Check my detailed post On HP AirPrint Setup - Andrew Myke Weebly