What device are you using? I use a Pico 4 and frankly this has never actually worked. I just use Virtual Desktop now and download videos to the headset (on the local internal memory) to view on DeoVR. I do wish that the USB drive worked, because I have a few of those Sandisk Extreme 1TB flash drives that are amazing - they are perfect for VR headsets, very small and light. But, alas, I cannot use them with DeoVR. However, I can copy/paste to the local headset storage. But that sort of defeats the purpose, I suppose. Plus, external devices do draw power. So not really the most efficient, either, especially in high bitrate content.
Sorry I cannot be of my help, but I am also curious.
