Report visual refresh

Hi all, 

My power bi data source is imported from one drive (excel files) and the dataset is scheduled to refresh once per day. What I don't understand is how refresh works for report visuals. After the dataset is refreshed, I saw that sometimes, the visuals are not reflected to latest data yet and I manually clicked the refresh button. But sometimes, I saw that the visuals are already updated to latest data when I checked after a few hours. 

Is there any timing like, how long does it take for the report visuals to get updated after dataset is refreshed?