NIGHTHAWK NOT ABLE TO STOP A CONNECT DEVICE

The mobile nighthawk shows the connected devices to the router. When I pause the internet for a device, it does not stop it. The phone does show the device is blocked but it is not actually blocked. This started happening after the mobile apps got upgraded to latest version. I have tried connecting directly to the router from a web browser and tried to block a device which works perfectly. So, the issue is limited to only the mobile. I am using apple. 

The router is RAX45.

Any suggestion?