Time not being counted correctly

Whenever I listen to music I like to check how much music I’ve listened to that day and for some reason it keeps showing up as one to three hours when I know it’s been well over six. It used to be logged correctly, but now it’s not. It seems that if I listen to music on another device, but on the same Spotify account, it doesn’t register it or if I am listening to music while I’m at school and have no service.