When its night time hostile mobs won't spawn, and no underwater mobs spawn in the oceans / rivers. The only mobs that are spawning are farm animals and biome specific mobs like Pandas or Parrots.
How to replicate:
Create a new world in 25w02a, set the time to night, and observe that no hostile mobs are spawning.
I was just made aware that MC-279245 exists and has been closed! Apologies! Thank you all for the hard work you do!