@ethanosullivan As far as I know, there are no controls for Thunderbolt or even graphics card settings in the Framework’s BIOS
Some other questions I have, Do you have the Framework plugged into AC power when you are connecting the GPU? If not, the laptop could be attempting to draw power from the enclosure as well, which could definitely overwork that PSU if it’s trying to power the card and laptop.
Something else to look into would be your Drivers themselves. Since the topic suggests this is a DIY model, did you download and install the Framework Driver bundle for Windows from these forums? If not, it could be that Windows just downloaded their generic drivers which may or may not fully take advantage of Thunderbolt. I would try updating to the latest BIOS and installing their latest Driver bundle, which includes Intel Thunderbolt Drivers, and see if these issues persist. Make sure you get the Windows 10, and not their Alpha for Windows 11.