WhatsApp app not launching / opening on iOS / iPhone (Supervised).

Can this be a corruption, a re-install (remove / re-push).

I see this installed originally via a users iTunes account (WhatsApp) and it showed as "Unmanaged" in the Apps section in JSS. Now it seems that the MDM / CP applied and now it only shows our 11 apps.

But the WhatsApp app will not open?

I suppose I have to remove the app and re-push, but how to do that if I am pushing to a Smart Group based on "Model", iPhone 7.

thx in advance, john