Hostel mobs not spawning

Hostel mobs spawn very rarely in my survival world. I have traversed many caves and not found a single mob.. The night is desolate. Very rarely a mob will spawn under a tree at night. I have tried switching to peaceful mode and back to hard. I'v tried restarting the game and my computer I cant think of what else to do. The world was first generated in 19w09a so that might be the problem. I don't know why no one else is having this problem.

P.S: The useless traveling villagers are popping up everywhere make them stop