I cannot find the printer when using AirPrint or iPrint&Label on iOS10 and connecting to my printer in Ad-hoc mode.
The issue may occur if you are using iOS 10.1.1. or earlier.
To resolve it, update your device to the latest iOS version (10.2 or later).
If the IP address is set to [STATIC], you may not be able to print. On your Apple device, tap [Settings], then [Wi-Fi] and tap the [i] icon next to the printer you want to change. Tap [DHCP] and then exit the settings.