@Robobird I'm in the same situation when the blocking device says it's unblocked but can't reach the internet.

Here's what I did:

- Blocked a device and left it like that until the next day.

- The next day I used the app and the "blocked" device now shows as an "unblocked" device. 

- I proceed to use the device but it says it can't connect to the WiFi.

I've removed the device from the network using the app and also removed it manually. I restarted the TV and nothing happened.