I recently purchased a HP OfficeJet 3830 multifunction printer which has all the bells and whistles that are expected nowadays, such as AirPrint. After upgrading to iOS 11, I wasn’t able to print from either my iPhone or iPad anymore. The printer would still appear as an available AirPrint printer and I could set the print options, but iOS would just hang at “Contacting Printer”. I could still print from a PC and Mac so the issue was between the printer and iOS.
I tried rebooting the printer, resetting its network settings, and restarting the router, but none of this had any effect. I spent some time on the HP forums and discovered this isn’t uncommon and that there’s an easy fix—disable IPv6 on the printer. Once I did this, I was able to print from iOS again.