Please help me

I saw this video: https://www.youtube.com/watch?v=EuWb3Hy5m1M&t=327s

Where they teach me the components of a rig, but buy another mother card by mistake.

I had to buy the MSI Z170A https://www.amazon.com/MSI-Enthuastic-Z170A-Motherboard-M5/dp/B0131GA4WI/ref=cm_wl_huc_item

And buy the MSI h110
https://www.amazon.com/gp/product/B01B4U47E4/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

But what a fool I am

the h110 you have only 3 input video cards, and buy 6 rx580 video cards

to solve buy a PCI-E 1 to 4, which converts the main input to 4 inputs, and so I can connect the 6 cards

the problem occurs when I start with 5 video cards or more, the PC does not start the screen stays black

but when I start with 4 video cards or more, the PC works excellently

I'm using simplemining, I wanted to know how to solve, help please