DL580 G7 with PCI express passthrough

[CyberianSoldier]

So a few weeks ago I started work on setting up a GPU passthrough lab machine, it's was running on a 7th gen dl580 using vmware ESXI 6.0 Update 2. I got everything working with two videocards, but the project scope was to get 5 or more VMs with dedicated videocards running, so I ordered a PCI-Express expansion board, it arrived and I installed it last night, now PCI Passthrough doesn't seem to work at all, even on the two working virtual machines. I checked and VT-D is still endabled, and so is virtualization support. So what is going on? has anyone run into this before when installing PCI Express IO expanders?

System so far:

CPU: 4x E7520

Memory: 88 GB (in 4 GB Sticks)

HDD: 2x 300 GB 10k SAS drives (PERC-i ?)

HP DL580 G7 PCI-E I/O Expansion Board 512845-001 591205-001