Weirdly enough, retrying this, I accidentally clicked inside the window: moving the mouse in the guest seems to unstuck the process for a while (I had to repeat this 5 time to get until the end of the erase process)!
Weirdly enough, retrying this, I accidentally clicked inside the window: moving the mouse in the guest seems to unstuck the process for a while (I had to repeat this 5 time to get until the end of the erase process)!