played plo cash with bonus funds and only preflop rake counted somehow

Just realized after a session grinding PLO cash with some bonus funds, only the preflop rake seemed to get counted toward unlocking the bonus, not any of the real action after the flop. I was definitely mixing it up post-flop, so this threw me for a loop. Is this a standard thing at some places or did I just find a weird exception? Makes me think twice about burning my bonus on tables with lots of multiway action if most of it isn’t even getting tracked. Anyone else seen this or figured out a way around it?