Magma cubes in all sized don't attack iron golems and snow golems even under attack of these golems. On attached screenshot you can see magma cubes are ignoring iron golems while slime are hostile towards them. In order to reproduce:
1) spawn iron or snow golem
2) spawn magma cubes
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We're actually already tracking this issue at MCPE-51162, so I will resolve and link this ticket as a duplicate.
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