First thing I did was the bios update to 810 then enable '4G decoding'.  I started the bios setting at gen2 for all without success and then gen1 for all without any success.  I then tried leaving everything on auto and just setting the pcie configuration on gen1 and all seven cards were recognized.  After all the video cards were seen, I didn't try adjusting the setting at all.  It took a weekend to get my rig up and running I didn't want to test to see if there were gains to be made from setting anything on gen1 or gen2.  

I am also using the blue 006C version.  Odd thing is the first eight I ordered from Amazon came with the little tabs that lock the riser on the card but the second time I ordered it, it came without the tabs but seems to fit much tighter on the card.  They are both working fine though.  I ordered the second set thinking it was the risers that was causing the original problem but that wasn't it.

On a side note my two MSI Armor Geforce GTX 1070 OC Edition 8GB seems to run the hottest at 60-64 degrees.  Others are in the 50-55 range.