Hello,
Could you login to router's WebUI, navigate to Network -> Firewall -> General settings, open lan zone settings, and check, if Guest network is not added in Covered options field, as in the screenshot below?
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=13380828004850587537)
If you find it sitting here, remove Guest network, save the settings and try again.
Best regards,