Spawning a magma cube with glowing set to 1b, and the invisibility effect, causes the outline to be overridden to white, and rendering artifacts to occur when viewed from below. The entire magma cube turns white, and can be seen through other glowing objects.
The command used to summon the magma cube was as follows. Place in a command block or mcfunction file to reproduce. The team 'green' must also be created, with color
set to green
.
summon minecraft:magma_cube ~ ~2 ~ {NoGravity:1b,Silent:1b,Invulnerable:1b,Glowing:1b,Team:"green",PersistenceRequired:1b,NoAI:1b,CanPickUpLoot:0b,Size:1,ActiveEffects:[{Id:14b,Amplifier:255b,Duration:1000000,ShowParticles:0b}]}
I have also uploaded a video where you can see two identical magma cubes, where the one on the right does not have the invisibility effect. As you can see, it renders correctly with a green outline.
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This is already tracked as MC-166397, feel free to add additional information there.
I just messed around with it a bit further, and it appears that by using the glowing effect rather than the nbt parameter, the rendering glitch no longer occurs.
summon minecraft:magma_cube ~ ~ ~ {NoGravity:1b,Silent:1b,Invulnerable:1b,PersistenceRequired:1b,NoAI:1b,Size:1,ActiveEffects:[{Id:14b,Amplifier:1b,Duration:1000000,ShowParticles:0b},{Id:24b,Amplifier:1b,Duration:1000000,ShowParticles:0b}]}