Avatars

Help please: 

      I have an avatar that will display if I start the meeting and am the host.  It will show up when I turn the video off and disappear if I turn the video screen on.  This is what I want to happen.

       That same avatar will not display if I join a zoom meeting where I am merely a member of the class. I do not act as host.  If I turn the video off, only the traditional black square appears.  I want a zoom black square containing a picture of the avatar whenever I turn off the video.

     Other people attending this zoom meeting have avatars.  Therefore, I doubt that the host's settings prevent an avatar from being used.

     I have an Apple operating system 12.6.3  + zoom operating system 5.13.7 

   Can anyone educate my ignorance?