Turn off DHCP on the second router. Teir2.
If it's on, that's the issue.
Further if you are connecting the tier 2 to the WAN port, you will more than likely have to plug into one of the 4 ports on the router. The WAN port would block the DHCP of the first router.
So the routers are connected LAN port to LAN port, not LAN port to WAN port.