Hello! Making A choice between you and Bryant does cause one of the fragments of B and C to increase. This is normal flow, not a bug.
The reverse ending fragments is not one of the BCD fragments, but the A fragments (also called star fragments), which you get when you complete the HE for the first time. If you want to quickly collect reversal endings, check Walkthough to quickly collect HEs!
Anyway, thanks for the report! let me know if you find any more bugs! Thank you for playing the game^▽^