The Bug

When you have falling_block and you use the gamerule doImmediateRespawn, a lot of visual glitch happened. Falling_block on passenger disappear and appear again after death, Falling_block in the falling state stay visible in a glitch state.

How to Replicate:

-Open a world

-Do

/summon minecraft:armor_stand ~ ~ ~ {Passengers:[{id:"minecraft:falling_block",Time:1,NoGravity:1b}]}

-Do

/gamerule doImmediateRespawn true

-use /kill or any method you want to die
-watch the armor_stand and you will see, the falling_block is no longer visible (but still here) and if you die again it will appear again

Other Example:

-die when falling_block are falling when doImmediateRespawn is active and voila.

Observed Result

The falling block was visually glitching up and down

Expected Result

The falling block wouldn't visually glitch