I don't know what is going on in skyblock

In sky block 2 mobs aren't spawning.

 

What do you mean?
Is it a dark room grinder, or a mob spawner?

 

dark room grinder

 

Are you 24+ blocks away from the grinder?

 

yes

 

It's probably because of the fact you're in multiplayer.
Due to there being multiple players, the spawn rates are greatly decreased.

 

But it was working before it with like 50 people on sky block

 

Its working again