A few weeks ago, a member of my server contacted me about an auto-teleport bug that only occurred when the player went under y=2 (or y=3, it changes depending on your area.)

I tried this myself, and it wasn't a lie or anything. It started when I had a texture pack on, specifically the "SCP Modern Base Textures" that I had downloaded roughly a month before.

The End seems perfectly normal, other than the End Portal to The Overworld and the portal to the Outer End Islands are made of obsidian, and the smaller portals in the End Void.