Valve just released a beta version of the long awaited Panorama UI.
When this update is released it will more than likely break metjm.net because it completely replaces the inspect function which is used to render screenshots.
I don't know when this will happen, but you can get a list of the screenshots you requested here: https://metjm.net/myscreens/
Download them if you want to keep them. No idea when Vale will release the update, but better safe than sorry ;)