slot challenge counted spins in real mode but ignored same spins with bonus balance

Was doing this silly slot challenge last night to see if I could make it through 500 spins without rage quitting. Started on real balance, no problems, spins all counted. Then after I hit a small win, I swapped to my bonus balance, and surprise - the counter just pretended those spins didn’t exist. Burned through a bunch and didn’t get credit for any of them.

Does this happen everywhere or did I just pick one of the casinos with screwy software? Noticed this before but always blamed it on bad WiFi or too many tabs open. Do any of you actually track spin counts when flipping between balances, or is this some hidden “feature” I should just expect?