Avatar icons and some images are no longer displayed

For a few weeks now, the avatar symbols (icons) are no longer displayed in the Battle.net application, I only see the names of my friends. My own avatar image is also no longer displayed. Instead of the picture, you only see the background of the application. Furthermore, in some news or articles no pictures are displayed, or only the name or placeholder text of the picture is displayed. As we know from HTML, if an image does not exist, the text of the alt attribute is displayed, and this is exactly what happens here. Is there a workaround to get the images displayed again? E.g. delete a cache or something? I have already uninstalled the application as stated in the forum and deleted all the associated TEMP and AppData files, but the same thing always happens, that no pictures are shown.

Please help or correct the problem described.

With kind regards