No devices were found with Ubuntu 20.04 + RTX 3060 Ti eGPU setup

I’m trying an eGPU setup with a Thinkpad X1 Carbon Gen 10 laptop running Ubuntu 20.04 (Linux kernel version 5.14.0-1059-oem). I install the nvidia-driver-530 driver (also tried versions 525, 515, 510, and 470) using the Additional Drivers menu. After rebooting, running nvidia-smi gives No devices were found.

Running lsmod | grep -i "nvidia" gives

nvidia_uvm           1277952  0
nvidia_drm             65536  0
nvidia_modeset       1273856  1 nvidia_drm
nvidia              55717888  14 nvidia_uvm,nvidia_modeset
drm_kms_helper        258048  2 nvidia_drm,i915
drm                   557056  16 drm_kms_helper,nvidia,nvidia_drm,i915,ttm

Running lspci | grep VGA gives

00:02.0 VGA compatible controller: Intel Corporation Device 46a6 (rev 0c)
22:00.0 VGA compatible controller: NVIDIA Corporation Device 2489 (rev a1)

Running gives, among other things, Failed to initialize the NVIDIA GPU at PCI:34:0:0.

I’m aware of workrounds for Proxmox (i.e., echo 1 > /sys/bus/pci/devices/0000\:0X\:00.0/remove,
echo 1 > /sys/bus/pci/rescan) as well as kernel parameters such as rcutree.rcu_idle_gp_delay=1, but nothing I’ve tried works. I know that the problem is not with the GPU or the enclosure, since they work fine with another laptop.

nvidia-bug-report.log.gz (333.6 KB)