i am trying to delete all the tasks created by an user when the user deletes itself

await req.user.remove();

userSchema.pre('remove',async function(next){
     const user = this;
     TaskModel.deleteMany({owner : user._id});
     next();});

but this doesnt delete any tasks created by user.

1. It deletes when i await TaskModel.deleteMany(); I fail to understand this behavior.
2. It also works perfectly when i add simple callback via then() to TaskModel.deleteMany();

My understanding is that if it doesnt delete when i dont write await then it also should not delete even if i write then callback.