Ended up figuring it out.
I pulled apart half of the H1 Chassis to be able to fit the GPU directly into the motherboard and it worked fine.
I then determined it was the Riser cable so I got NZXT to send out a replacement only to still have the same issue.
It was then I found out that CPU & PCH...
Thanks for the suggestion.
I've tried reseating both the riser and GPU multiple times
I've tried a different PCI-E output on the stock modular NZXT H1 PSU
I've tried a different PCI-E cable that came with the Case/PSU
I put an old GTX650 in that I had lying around for years and that didn't spit...
Just Built this little ITX quickly to take with me while working away for 4.5 Months
3DMark CPU Bench passes fine no issues however Timespy & Firestrike crashes (I assume every other GPU Benchmark too)
Tried Firestrike once lasted less than 2 seconds, Timespy normally crashes after 5 or so...