In the Temple of Eterra I have found a corner element that is not faded out, when the player walks near the curved wall. It’s most likely two wall elements connecting together, where one element does not get clipped along with the original tile.
Find below the pics in .zip packs due to extension restrictions.
corner_with_ui.zip (1.5 MB) corner_without_clipping.zip (3.2 MB) corner_without_ui.zip (2.1 MB)