Unfortunately, apart from uninstalling the Fingbox and reinstalling it, there is no way of updating the SSID. . This is because the SSID is saved in the network when the user performs the scan using the Fing App (also when onboarding the Fingbox). After this 1st scan, all other scans are being done by the Fingbox itself, but since the Fingbox is connected through a wired LAN cable, it’s not capable of detecting new SSID(s) in the network.
How to view/switch between multiple networks on Fing app
Why has my Fingbox gone offline?
Why is there a delay in blocking devices?
Why Fingbox produce so much traffic on my Network?
Can the Fingbox monitor multiple/guest networks?
Changing E-mail Address Associated with Fingbox/Fing Account