Building a third rig and decided to use the z270 instead of the TB250.

I have:
2x 8GB DDR4
i5 7400
EVGA G2 1300w
2—Geforce 1080 TI via PCIE 16
1—Geforce 1070 via riser
Windows 10 x64

The board is only detecting the 2 1080ti and not the 1070. Any suggestions?
Tried many configs but no go.

Thanks!