For roughly the past week, I've been unable to see my tracks in Explore Web.

As you can see at the bottom of this screenshot, I have 353 tracks saved. They DO show on the map, but they never load in the sidebar - the spinner keeps going indefinitely (have left it for hours, no change). Same result across multiple browsers on multiple devices. Clicking a track on the map does pop up an info box, but does not load the track name and the edit and collections buttons are non-functional.
Obviously this severely degrades the functionality of the product. With it being across many devices, this looks like it's on the server side of things. I did a full reset on the device and re-synced it with no change.