Amount of hours completed glitch [已解决]

Whenever I go to practice for usually about an hour, it usually displays the added time I've put in, where the collective amount of hours you've practiced goes. Well for the past few days I've been practicing for a pm hour at least but the very next day I go back to check my completed hours( I have at least 6-7 hours put in for the past few days) it always pushes it back by an 1 and a half. Meaning that the time I spent practicing usually ends up not being added whatsoever, usually being stuck around 3 hours and 30 mins. Has anybody had a problem like this before?

Can you say more about "it always pushes it back by an 1 and a half"?

Like it sometimes reverts back to the time is was before i would do a drawing session, basically not adding the added time spent. For example, if i practiced for 6 hours and say 19 minutes. The next time i would come back, it would say something like 5 hours and 28 mins, or an odd number of time subtracted. This would often sometimes happen when refreshing the page after im done. Sometimes it would'nt even display it.