Battleground timer erratic

I never use to have a problem with the timer in battlegrounds. But recently, I’ve found I have 80+ seconds on turn 4 or 5, where players don’t really need that much time, and yet sometimes I only have 40 seconds on turn 11 onwards, when players boards are far more complicated and they need MORE time, not less. It use to be the case that end game timers were 80+, why the change?