Magic Keyboard not working following iOS update

This morning I updated my iPad Pro to iOS 14.4.2. When I opened the iPad after the update had completed there was a pop-up stating that “this accessory is not compatible with this device”. Since then my Magic Keyboard has not been responding, neither the keys nor the track pad nor the charging, nothing is working.

I restarted the iPad but this has not helped. Has anyone else experienced the same or can anyone suggest a fix?