http://3cbzkrvakrpetjjppdwzbzqrlkmzatjs7jbyazap5gwutj32gcltjpqd.onion
I plugged it into the next slot along which is a PCIe*8 slot that’s open ended so it takes larger cards. The upside of this is that the system is still working well, the downside is that the issues I already had with the GPU being unreasonably large are exacerbated by losing one of the *16 slots.