There's a problem with the app, not Samsung fault but have read today that after a certain update that WhatsApp carried out it knock off the app for some device's. I do know that Google have admitted about they server problems which started showing some apps Samsung Wallet plus a few others were spying on it's customers and Google play store protect was informing people to uninstall the Samsung Wallet by mistake. I do believe that has now been rectify but I'm not sure about the WhatsApp if that has been.
