While using a zombie xp farm in a single player 1.16.4 world, I noticed that looking through the mass of experience orbs caused the chests to become transparent (in areas looking through the experience). I could clearly see the cobblestone texture underneath the chests.
Actually, it's MC-191137 if it's still an issue in 1.16.4. This shouldn't be an issue with Fabulous! graphics settings. If you're using Fast or Fancy, then this will not be fixed, unfortunately.