I am trying to extend the range of my Sagemcom 12 Box modem/router by using a C9 set up as a WDS bridge according to the guide. IE, move the IP of the C9 into the subnet of the root router, configure WDS, disable DHCP.

While my Android phone and my Chromebook connect to the C9 Wifi bridge without issue (using DHCP for auto-configuration), my Nvidia Shield TV Pro (2019 version) can't access the internet through the C9 Wifi bridge. If the Shield uses DHCP to configure the IP it doesn't get an IP, if it uses a static IP it winds up without internet access. In either case connecting to the C9 Wifi bridge does not complete with the normal notification that a connection was made succesfully with the Wifi network. Frustratingly, if I set up a mobile hotspot on my phone which uses the C9 Wifi bridge, the Shield can connect without an issue.

It appears to me that the Shield is simply not compatible with something the C9 is doing, but I don't know what and if the C9 can be configured differently to handle it. I would appreciate some thoughts and guidance.