Hostile Mobs don't spawning at night or in caves

Does this only affect a specific world, or every world?

I created a new world to test and it is working, but in my primary world created in 1.21.9, after the update becomes to have this problem.

Create a copy of your primary world, turn on cheats, and then run /kill @e. Do mobs start spawning? If so, this means you reached the global mob cap.