From my experience the male will eventually learn it. I have had the same with one male, – I think it mainly happened because he was unable to get the eggs to sit in the bubblenest, – so they kept falling to the floor of the cave.
When the eggs fall out like this, – I suppose they are nothing worth really, – so it makes sense that the male eats them instead. That way the nourishment in the eggs are not wasted.
My male eventually learned and got quite a lot of fry.