I can usually get it to work. The few times it hasn't I've called and they've sent someone up to fix it. Depending on how quick they are, that might mean that you miss out on a night though.

Connecting through the app rarely works but getting the code from the website works well.

I can also get my own personal one to work in a hotel that doesn't have it but that takes a bit of technical knowledge and two devices (I always have a tablet and a laptop so that's no problem, but if you are traveling with someone two phones works as well). Also I've forgotten about 3 of them plugged into the back of TVs in various hotels around the world. Good thing they are cheap.