Static IP with wireless bridge

I have a pretty simple network with the main router being a Netgear R8500. I am using an ASUS RT-N66U router in repeater mode to connect device on another floor via wireless bridge including a network printer and a file server.

I need a static IP address for the printer and file server, but every time I assign one, it changes when the IP addresses refresh (usually a day or two). This is because all of my devices that come through the wireless bridge show the MAC address of the wireless bridge, so the main router that assigns IP addresses doesn’t know which one is the correct device.

Is there a way to fix this? Every time I set up a printer on one of the computers, it works for about two days, and then I have to go in and change the IP address.

Thanks!