This is what happened to my arai back in February when I started riding. This was only after a week of using the helmet. The rubber trim on the chin bar that became unglued. Maybe the hour long ride in the cold messed up the glue. The “superb” quality of arai is not all that it’s crack up to be.
My previous helmet had a tab fall off (the ones that hold the chin pads in). The last time, I went back to the shop and they just re-glued it there for me. So this time I figured I'd do it myself. I just epoxied the thing back on carefully to not make a mess.
It was a Saturday night too, so I'd have to wait till a Tuesday, and if the send it away, then I'd have no lid for those days.
It's no biggie, but just a pain in the ass that both my arai's have had things become un-glued. My HJC never had anything fall apart.