Like the other said its a power issue I think your motherboard needs more power to run your 4 cards.
I experienced this on h110 btc pro when adding 1 more card in my rig its getting issue then I put the I add the 2 molex cable near to pcie x1 sockets and everything it works fine so you need to put a molex cable in your motherboard near PCIe socket.
I added the connector from the PSU to the molex connector and it seems to be working... thanks for the advice
