We had the exact same issue 2 weeks ago - at one point there were 3 carpenter bees fighting each other for the territory of our villa. They disappear around the time you want to sit in the jacuzzi for sunset, so that was the only time we managed to get outside and use it... was quite frustrating, but Quiet Zone became our oasis as a result.
We called it in, and they sent some exterminators which sprayed all sorts of stuff whilst we left the room for 2 hours. But it made no different, they were back with vengeance the very next day...
The bees like the wood - they try to find holes to lay eggs in - and then want to protect the space after and fight away other bees. Might be seasonal? We resigned to the fact that we were the intruders. Good luck!