Group SP Site (Group image/logo Not Updating)

Brent Ellis 

I am seeing the same behavior and I have been fighting with it for days.  This is horrible, I cannot deliver a (OOTB) out of the box solution to the customer, let alone a custom one.   Nothing out of the box works the way it is documented and randomly executes its own behavior.  This regardless of what size the image or any of its attributes or properties.  I am using the modernUI Change the Look => Header => Site logo => Change.   Then save of course..

1. First it was the translucent background that worked but then randomly changed to black background on its own once the site icon was in place.  I eventually changed it to a common background that was the same as the rest of the site to hide it.
2. Later for whatever reason about a week from that  it changed on its own to https://some_site/sites/some_site_collection/_api/GroupService/GetGroupImage?id=%2759deda41-79a3-443f-bce3-70f8da4f9924%27&hash=636928672156641901
3. Changing it in the old Title, description and icon location /_layouts/prjsetng.aspx worked for a moment then it would change back to item in line number two.
4. I changed the group icon from inside outlook and it never updated except in outlook.  It is still doing the same thing as line item two.  This appears to be a REST call for what reason or purpose I have no idea.