There are some strange errors that might be part of the reason it's not being detect by Linux, like these:
Jul 7 19:54:01 otfgserver kernel: resource sanity check: requesting [mem 0x000c0000-0x000fffff], which spans more than PCI Bus 0000:00 [mem 0x000c0000-0x000dffff window]
Jul 7 19:54:01 otfgserver kernel: caller _nv000908rm+0x1bf/0x1f0 [nvidia] mapping multiple BARs
Jul 7 19:54:03 otfgserver kernel: resource sanity check: requesting [mem 0x000c0000-0x000fffff], which spans more than PCI Bus 0000:00 [mem 0x000c0000-0x000dffff window]
Jul 7 19:54:03 otfgserver kernel: caller _nv000908rm+0x1bf/0x1f0 [nvidia] mapping multiple BARs
Jul 7 19:54:06 otfgserver kernel: resource sanity check: requesting [mem 0x000c0000-0x000fffff], which spans more than PCI Bus 0000:00 [mem 0x000c0000-0x000dffff window]
You can try another slot, look for a bios update, etc, but this is still true: