iMessage showing some, but not all, messages
I have a Verizon iPhone 5s OS 8.4 and a Mac Mini OS 10.10.4. I enabled iMessage on my iPhone.
On my iPhone iMessage settings panel, I don't have anyone on my Blocked list, and the 'Send & Receive' subpanel has my mobile phone # selected (my gmail account, which also shows up, is not selected).
On my Mac Messages app, it shows a Bonjour and Google Talk account as inactive; then, my iMessage account is active and enabled. There is nobody on my Blocked list.
I have tried every permutation of signing out and signing back in to iMessage on my phone and mac. Still, there are recent messages that show up on my phone, which do not show up on my mac. When I get an incoming text message on my phone, sometimes it also shows up on my Mac, and sometimes it doesn't.
If I browse to vtext.com (Verizon's own web-based messaging app), it is perfectly synced to what is on my phone.
How can I get my iPhone and my Mac Mini to be exactly in sync with incoming text messages?
iPhone 5s, iOS 8.4