The bug

When you are outside of water or lava you see its surface, when you are inside it you see the water or lava tint. However, at certain hights you either see neither the surface nor the tint or the surface and the tint (see attached videos). The first one allows to easily see through large areas of lava or water. This happens in all gamemodes but can be seen best when you are able to fly.

How to reproduce

No surface and no tint

1. Switch to Creative mode and start flying
2. Use the following commands

   /setblock ~ 64 ~ lava
   

   /tp ~ 62.39 ~
   

3. Start looking up and down
   → At some point you will see no bottom surface but also no tint

Surface and tint

1. Switch to Creative mode and start flying
2. Use the following commands

   /setblock ~ 64 ~ water
   

   /tp ~ 63.39 ~
   

3. Start looking up and down
   → At some point you will see the top surface and the tint