Even though this thread is quite old I'm wondering if there is a solution to this problem.
I recently retired my X-T2 as my main shooter and tried using it with an Elgato Cam Link 4k. The picture quality is great, but the camera is unusable as a webcam because of its constant freezes. I already tried using different SD-Cards or even no card at all. Aditionally I have tried using it on bateries aswell as on main power through the barrel plug on the battery grip. No matter what I tried it kept freezing in random intervals.
The bodys and the lenses firmware are up to date.