Thanks to all who responded. 
I believe my problem occurred when I performed the most recent upgrade to Gnome 45.1. When I performed that update, I hadn’t disabled all of the pre 45 gnome extensions. This was mandatory before performing the update. When I rebooted this caused a problem which I previously posted about in another section of this forum and which I thought I had resolved. Apparently I was wrong and I believe that’s why I experienced this key ring problem when I tried to perform the next update which included a gnome extension update.
Anyway, I think I have solved the problem by following ALL of the steps outlined in this well written HOWTO: [HowTo] Solve Keyring Related Issues in Manjaro.