When I have my 2015 MBP awake and my iPhone is nearby, sometimes I receive a message and neither my Mac nor my iPhone notify me, which means I don’t know I received a new message.
If I go into the Messages app on Mac or wake the iPhone, I can see the message.
It’s almost as if both devices think another device is notifying me. I do have a 2011 MBP around but I am signed out of iMessage on the Messages app on that computer.
A month or two ago I signed out of Messages on the 2015 MBP and nuked the Messages database. Set it up fresh, had to sign in again, wait for messages to download from iCloud, etc. It seems to solve the problem (and fix out of order messages) for about a week. Then the problem behavior returned.
MBP running macOS High Sierra 10.13.6. Using Messages in iCloud on both devices. Bluetooth is enabled on both devices.
I suspect this is a bug with Messages on Mac. Anybody else run into this issue and if so have you been able to resolve it?
Edit: it’s my experience that if Bluetooth is turned off on the iPhone, this issue doesn’t happen. In that case both Mac and iPhone both seem to always show notifications for new messages. However turning off Bluetooth on iPhone isn’t ideal, as you might imagine.