Update to my report of this problem on the 17th.
I re-enabled my browser guard intending to turn it off when I was going into Facebook. Forgot to do that this morning and I noticed in "Share" option of Facebook that it now had an option of "Share now (Custom)" which didn't recognize so I used another option.
Anyway I then noticed that my Contacts list was displayed as usual. I was concerned that I had left the browser guard disabled but it showed the normal blue M icon. I double checked and it was on with Facebooks loaded and all protections enabled. I checked the guard version and it was still on V 2.2.18 and had not Vivaldi updates or Windows. Perhaps Facebook has been rolling out changes (Custom share?) and I got the changes.