Mac Messages not syncing with iOS

Messages on the Mac (El Capitan 10.11.6) stopped receiving iMessages (6s - Latest iOS) I've sent from both my iPhone and iPad (9.7 Pro - Latest iOS)

Furthermore the Mac isn't recognizing previously recognized contacts, and when one is selected the name shows up in pink, not blue, or allowing me to send to specific phone numbers...only email addresses

Any thoughts on how to fix?

--Mitch