When fireworks (in my case spawned by a command block via summon (lifetime of 2, so they explode right after start)) are rendered on top of another transparent queued surface ike water, the water becomes invisible and blocks below water surface become visible.
I encountered the queue error during my own developments with unity, writing my own shaders for double culled surfaces.
The firework particles are rendered additive against a transparent dynamic plane.
This also results in color issues (darker in some corners) while blending with the background blocks below the water surface.
It seems like the queue for the firework shader has to be moved.