Black pointy tip cap and some of them are dying too soon when it’s small. They appear as blackish green. What’s happening?

Hey guys first time grower here x have been harvesting it but then after 1 week or two I started to see some black pointy tip cap and some of them are dying too soon when it’s small. They appear as blackish green. Anyone knows what’s happening? Tryp answers: Aborts. Pick them they won't grow further