Like for example right after the boss at castle of storms, you activate a lever and the left elevator drops down and the right goes up. But sometimes the elevator takes off immediately and you can go down asap, other times the elevator leaves while you're still pulling the lever and you have to wait for the elevator to return. I've seen it in various runs posted here, some runners have to wait for the elevator others can take the elevator immediately. Any one else noticed that, anything you can do about it or is it rng?

The elevators are likely on a global timer regardless of if they're active yet, so nah nothing you can do about it