Album counting minutes incorrectly

The album ‘Cassie (U.S. Version)’ I’ve been listening to for a while. When I look at it, the minute count is around 850 mins, however if I go to my track leaderboard for the album and manually count it up, it sums to almost 1,300. I’m not sure why this is. Also I am making sure to count the minutes rather than the streams. Thank you.