Footage transfer to PC not working

I am trying to mass transfer recorded footage from my Quest headset to my computer. Despite there being hours worth of footage on there, when I plug my Quest into my PC it tells me the folder is empty. 

This comes after I mass deleted all footage previously in the folder naively thinking that it would delete the footage off the headset also (how silly of me!) as this was before the ability to delete more than one file at once was added. The files no longer show up in the folder on my PC's file explorer - neither does any of the new footage - but they are certainly still on the headset. 

So yeah, now the whole thing's buggered. No idea how to fix it, I've tried plugging my cable into different USB ports, disabling then re-enabling the USB dialog thing, no dice. My only other alternative now to get this footage onto my computer is to spend 2.5 hours uploading it to Google Drive and hoping to God that no ridiculous glitch happens that stops the upload and forces me to do it again (which has happened in the past). 

Any help would be appreciated, really at the end of my rope with the Horizon OS software. Cheers.