This thread was from 4 years ago, but it seems a group of people on here were starting with early versions of this motherboard from China, and it seems they needed power to all Molex connectors (I guess the newer versions use 6 pin connectors) next to the GPU's even if the GPU slot was empty...............does this make sense?
I would say no. The labeling suggests the slots are powered individually. If the slot power is interconnected
any slot should be able to draw power from any connector, as long as there are enough connections to power
all the installed GPUs.
Bypassin it with a riser would be a good test.