iMessages on Watch and iPhone
There are several threads regarding iMessages notifications not coming through. For my situation the problem started when I got an Apple Watch. I need to be woken up for my messages from the paging service and I was wearing my Apple watch at night (nice to know I don't have sleep apnea). However, the problem is the watch notification is too subtle to wake me from a deep sleep. I think the solution is that when on call I will not wear my watch. Once off my wrist it locks and then notifications go to my iPhone which is much louder and more persistent.