I just noticed that it’s the same on WordPress. The email will not change via the WP profiles too. I’m really frustrated at the moment.
Edit:
I’ve successfully changed it. Since BuddyPress and WordPress are linked together, you can go to: https://wordpress.org/wp-admin/profile.php and change your email there. The system will send you a confirmation email and once you confirm it your email is changed. You could do the same on BuddyPress but they decided to block any attempt to visit the back-end pages.