My syncing issue started today, 8/12/2019. Only 1 person I texted with today has updated on my Windows 10 desktop. All other texts today have not synced. I restarted computer, disconnected my desktop from Message +, reconnected and the same texts are there as before I did all of that.
I haven't changed any Verizon information in many years. The only thing I see on my desktop is Windows Defender Security updates today and each of the past few days.