@HaiTran 

Hi, Thank you for the feedback.

Do you mean TV and mobile, laptops, are connected to Deco and work fine, but they did not show up on the online device list?

---Are they all connected by Wi-Fi?

As for "Some devices already blocked still access into internet and show as offline"

Will you still see this device on the blacklist, with the same MAC address?

I think after blocking this device, it might enable the private address and connect to Deco again as a new device.

"some app/network still can log in after being blocked", Do you mean under Parental Control>Filter Content, you manually added some APP/network into the blocked content and found they are still accessible?

May I know what are these apps/networks?

Thank you very much.

Best regards.