My Nighthawk Extender has failed for years

[Edit] - when I look at my connection settings on my PC when connected to the extender, there is no information populated in the DHCP section. So I am not being assigned an IP, gateway, etc from the extender upon connecting to it.

I went ahead and manually set static IP information for this wifi connection on my computer and now I am connected. So what I'm seeing now appears to be: although the extender and my PC have static IPs reserved in the router IPv4 table, when the extender is connected to the router, and my PC requests an IP from the router (via the extender), something during the handoff of the reserved IP address is not making it from the router -> extender -> PC. Either router is not handing the correct info to the extender, or the extender is failing to pass on the IP info to the client. Only by forcing my PC to request a specific IP, and having that same IP also reserved on the router, did it connect.

While this worked for one device,  not all devices can have static IPs reserved on both ends, either because their MAC address randomizes on every connection, or because they are temporary guests, for example. Plus, I have a limited number of reserved IP on the router, which exceeds the number of connected devices in my home.

So now the problem can be narrowed down a little more - after several hours

1) devices already connected to the extender seem to lose their assigned IP/gateway information and cannot retrieve a new lease from the extender
2) any device attempting to make a fresh connection once the extender stops working, is unable to acquire an IP address via DHCP through the extender.