As odd as it may sound, I don't know when the problem started. My forum has been active for years and I've never had any major problems before. A member recently said they could not change their Avatar, so it was then when I started looking at the problem.
Most recently I've changed from 1.1.10 to 1.1.11
I don't have many mods but the most recent have been "Aeva Auto embed Video" and I also added a couple of smiley sets recently.
When I navigate to Avatar settings, I have all permissions checked for each member group.