Grinding gears with Zwift Hub

I received my Zwift Hub a few weeks ago and wanted to give it a try today.
While mounting it and installing the bike was quite straight forward, I really struggle with grinding gears.
I don’t have issue when switching gears but I got a hell of a noise when giving higher watts and the whole bike feels like shaking.
Note that I have installed the exact same cassette as I have on my bike (Shimano 105 R7000 11/32)

I tried different things live remove/reinstall the cassette, and indexing gears.
(I have a video but can put the link here)
What can I try? Is it an issue with the hub itself?