So If I want to select on 3rd Apps, both only wifi or only data, I t doesn't work. The App in question still works.
It only works for system, and pre installed Apps.
We should get a message indicating the next.
Not working on Firefox, Samsung Store, @aloud reader,...
Try clearing data and cache in Play Store then go to app permissions and check of the plat store is currently authorised to use data, if not grant it permission.
Do you want me to select one of those?
No go to settings then apps like in this screenshot 
