We're running MM 3.8.2. We are getting reports (and I see it myself) of SOME custom user avatars being replaced by the generic avatar. This seems to vary by user, and even by client. For example, on Mac client and Web client, my avatar is missing. If I use the IOS Beta client, I can see my own avatar.
On the Mac client I've tried "clear cache and reload" but no change in behavior. Any ideas?