Same thing here. I'm contacting Google regarding the issue. I've noticed a similar symptom since I've been using an android watch:
my watch gets notifications on time but my phone doesn't react. When i clear the notifications from my watch, my phone sets off multiple notifications in a row. Example: text, text, email, email, email, email, email, text, calendar. It's very annoying.
Now my phone makes no notifications. I've changed all notification sounds to full volume, I turn off bluetooth completely and my phone only vibrates for calls and doesn't make notification sounds or turn on the display as they come in.
While connected to a bluetooth device, the notifications come through that device but nothing or vibrate only on my phone.