Hello, I am using Teams to deliver content to my classes and currently I create a weekly banner announcement. I always upload my own image to be the background for the banner. However, frequently this image will disappear once posted and the default grey banner replaces it. If I go into edit, the image is still there and may appear for a short afterwards. However, this has happened frequently and continues to do so.
Also the same thing occurs if an image is pasted into the post space. It appears for a short time and this disappears from view, only to reappear at some later time.
Sounds like a coaching issue. That is usually the case with images In teams. Just sign out of teams which clears much of the cache and sign back in and see if it helps. Also check web client to see if the issue is there via teams.microsoft.com