I just discovered something disconcerting and I ask here if this is correct.

Previously on United if I was offered the opportunity to buy up to Business Class on a ps flight (generally for $375) my fare code would change to Z class. I would then receive the 50% EQM bonus.

I just bought up to Business on an upcoming ps flight (for what I consider a whopping $535) and the fare code changed to PN. It also shows that I will earn 100% PQMs, not 150%.

Is this the new way? If so then buying up will no longer be my practice. Live and learn.