Mini can't connect thru ASUS RT-AC1750 B1

Bought ASUS RT-AC1750 B1 after Mini started getting bad lag through Linksys router, but I can't get the Mini to connect to/thru the ASUS to a Roamio Pro. I've tried DHCP and static addresses. Ethernet 75ft cable connection.

Any ideas?

Thanks

Mini can't connect thru ASUS RT-AC1750 B1