Very slow export (GPU acceleration apparently not working)

After a failed video export my export is way slower than before (e.g. less than 5 min vs more than an hour).

Since a video export failed (can't remember the exact error message, but it was Nvidia related) my export seems to not use the GPU anymore (GPU acceleration is selected, but no GPU usage shown in the task manager). I updated my GPU driver and reinstalled Premiere Pro with no luck so far.

Any idea how to fix this issue?

System:

Premiere Pro 23.4, Win 10, RTX 2070