I happened to discover that my Glasswire was out of date by 2 versions and never received any notification for any of the computers I have Glasswire installed on. Why?
We have not issued an alert yet for any version past 2.1.158 yet, but we plan to do so next month. With version 2.1.166 we found a bug that caused some firewall apps to appear in the incorrect category in our user interface (even though the firewall was functioning correctly).
https://www.glasswire.com/changes/