RESOLVED by iOS 11.2.6 update – SnapBridge Review

Upgraded to iOS 11.2.6 resolved the synch via Bluetooth is working again with Nikon D5600. So it seems problem is not in Snapbridge app, there was an issue with iOS. Regardless, it would have been nice if Nikon provided some customer updates.
Review by QwertyKeyboard:) on SnapBridge.