iPhone not registering bluetooth keyboard keystrokes I have an iphone 6 running ios 11.2.6 which I'm attempting to use with an apple bluetooth keyboard.  I can successfully pair the two devices, at which point the on-screen virtual keyboard disappears from text entry scenarios, so clearly the phone is expecting input from the keyboard.  However, when I type, no keystrokes are received by the phone.

If I turn off the phone and turn on again the keyboard works as expected.  Can anyone suggest a more elegant way of establishing the connection or maybe settings that might be interfering with the bluetooth functionality?  Wifi maybe?  This only seems to happen when I'm connected to a public (relatively slow) wifi.
Given that your iPhone and keyboard connect and work just fine when the iPhone is connected to non-public WiFi networks, most likely the public WiFi networks are using frequencies that interfere with the Bluetooth in the keyboard. I would guess that by powering cycling your iPhone, it renegotiates the Bluetooth frequencies with the keyboard which do not interfere. Other factors at work may be microwave ovens, wireless speakers, Dish satellite systems, power sources, badly shielded cables &amp; wires, and a host of other causes. Apple has a great rundown of things that can cause interference. 

https://support.apple.com/en-us/HT20154

We live in a world saturated with radio and microwave radiation. If the poor public Wi-Fi locations are in locations where there are other people with phones, Bluetooth devices, etc, I’m not surprised that things don’t work well sometimes.