May relate to and/or clone MC-35920 and/or MC-9553.

The bug

If a falling block entity is summoned which is also a translucent block, any other translucent game objects positioned behind that translucent block will not render. This only affects the Fast and Fancy graphics settings.

In addition, entities will not render behind it either in some cases - this seems to depend on the age of the entity, i.e. whether it came into existence before or after the falling block.

How to reproduce

1. Summon a falling red stained glass entity:

   /summon falling_block ~ ~ ~ {BlockState:{Name:"minecraft:red_stained_glass"},Time:-2147483648,NoGravity:1}

2. Place something translucent nearby
3. Look at this translucent thing from behind the falling glass

Expected results

The translucent thing would still be visible from behind the glass.

Actual results

That is only the case for Fabulous! graphics - on Fast and Fancy graphics the object is occluded by the glass.