Just an update about this group disappearing for me, mainly to thank all those who offered help. Thank you!
It's still pretty confusing. This has been a watched forum for me for many many years and I rechecked it after the new software. It used to work properly. The work around I chose was to put a bookmark on the top bar of Firefox. That is a quick and easy way to get here, but sadly it does not update and only takes me to the message in view when I made the bookmark. I can deal with that. At least I don't have to click incessantly trying to find my favorite place on ECF.
The function used to work perfectly but now disappears at random times. The others in my watched groups have always worked. The strange thing about it is that when I get a notification from one of those and pull down the bell icon, this group is not included even when I find there have indeed been messages. All groups are set with the same options.
So much ado about nothing, but stressing again my thanks to all who gave advice.