There are two methods how you can solve this issue:
(a) Please restart your modem / router.
1. Unplug both router & modem.
2. Wait at least 30 seconds.
3. Plug in the modem.
4. Wait at least 60 seconds.
5. Plug in the router.
6. Wait at least 2 minutes.
7. When the router and modem restart, test to see if the issue is solved.
(b) Please check if your device is able to connect to the internet properly (see question TQ00193 "My device is not connecting to the internet").