When you have time, remove the resonant head, check the inside lug-casing screws, re-torque all of them, not too tight, not too loose. Then grab the air vent from the inside and outside to see if it...

It's likely the press-fit air vent. If you watch my video, I explain how to gently tighten them.


https://www.youtube.com/watch?v=d1-1m2tZqtM&lc=z13perwp0lblshmvq22wvd44dprzsb1dr