Hostile Mobs don't spawn in 1.14

(sorry for the bad english) I just created a new world in 1.14, and in the surface don't spawn hostile mobs.

-I'm in normal difficulty (locked)
-Only the hostile mobs don't spawn (the animals and villagers spawn correctly)
-I have not changed the gamerule
-I don't have mods
-it's the fifth night (in the game)