It is a bit hard to find a meaningful title for my question. Let me try to explain what I just experienced:
I am working with WAB 2.4 and duplicated an app to keep the old one while testing some changes in the new version. In the new version I am using a different WebMap with a reduced number of layers. Still, when I use for example the Toggle Layer Widget, I get the full list of layers from the original WebMap. How can that be? Is the list of layers somewhere stored in the app? (I didn't find another widget yet where the list of available layers are show. And I didn't use the Toggle Layer Widget in the old version