Relates to or may even duplicate MC-195103, I can't be sure.

The bug

When certain things are positioned behind one translucent object, and in front of the other, the Fabulous! graphics setting will result in it being rendered behind both of them instead of only one.

How to reproduce

There are many different cases of this - refer to the attached screenshots. An easy case to test is looking at a stained glass block which is in front of an ocean, paying attention to the outline.