Does the stud go into the water jacket ? Seems like it shouldn’t.If you have a dealer near by and have warranty I'd certainly take it in. Otherwise if your on your own with it I'd remove the Y pipe, and inspect, May need to remove the Stud and use a thread sealant of sort perhaps.
I my self don't know. Likely it wouldn't/shouldn't, the threaded holes may be surrounded by the water though but I'm thinking where the end of the hole it certainly would, so if it got drilled a bit too far by accident It could have caused this.Does the stud go into the water jacket ? Seems like it shouldn’t.
Likely the base gasket leaking, but certainly rare to see. I did have a brand new Suzuki back in 2016 have a leaky base gasket right out of the crate. So it is possible.