Buses arrive early

I dont know why but the app isnt really correct. The schedule said the bus near my house will be arriving at about 7:26 but at about 7:20 it had already departed. From my house to the bus station takes 5min. I usually start going at 7:15. when I almost arrive, I see the bus depart and I have to wait for the latter bus.
It is not always late but it occurs sometimes and recently, it got worse. And it is really annoying. Please fix it.

Camelias3998 about Transit • Subway & Bus Times, v3.11