Finally got to test my new xtx50 under water with a couple of shallow dives. I noticed it makes a rattly whistling sound when I breathe above water. Is this a concern? Divemaster said that’s common for a new regulator when it is dry but pretty sure I noticed the same thing before the second dive when the reg was already wet. The reg performed flawlessly under water on both dives. I’m a new diver with a new set of gears so a lot to learn!