After failing to find an ITS from the website, I searched Google to find a 2012 message on this forum where JonB claims XAMPP's issue tracking system is "down due to security issues": https://community.apachefriends.org/f/viewtopic.php?f=16&t=51132&p=196940#p196940
My understanding is that XAMPP has not operated an issue tracker since 2012.
Considering that XAMPP is being marketed as a stable product, I hereby publically demand the issue tracker to be resurrected, or - failing that - a new tracker to be created.
Note that even this forum is badly buggy - the registration process goes into an infinite loops if one tries setting the right language.