The bug

I cannot get Magma cubes to drop Magma Cream in the Nether. I have yet to test the Overworld, but I'm pretty sure it's more relevant in the Nether. (I have played through survival and killed around 10 of the biggest Magma Cubes (And their smaller cubes) without getting a single Magma Cream. I might be EXTREMELY unlucky, but I really doubt it. and if I see another large Magma cube (and it's smaller cubes) drop one, I will delete this issue.) And once I have time, I will further investigate.

What I expect:

I kill a large Magma Cube and it's "Smaller cubes" and get between 1 or 3 Magma Cream

What happens:

I kill the large Magma Cube and it's "Smaller cubes", but they do not drop any Magma cream.