How to adapt background settings from a previous Zoom version. Currently unchangeable

From a previous Zoom-version I had the possibility to set as a background colors. So I've chosen the color black. 

The effect is now, whenever I start a ZOOM-Call the background is always black and when I try to select "none" in the menu it does not react and the background remains black unless I select one of the pictures as an example...only then the black background is exchanged by the new selected one. I did some testing with Microsoft Teams and there the black background is not there....and also testings on logitec software camera settings which show no black background. This proves me that there is a bug within ZOOM (!)

I'm looking forward receiving hints on how to eliminate that black background. thx!