Streaks Lost

Hi I’m an Official course learner. I usually switch between IOS Application and web app. It happened two times that I did my daily course on my IOS app but it doesn’t sync with the web and the next day , all the streaks are gone!!
but funny thing is that after checking to see my streak is OK on web or not, it’s OK!! but next day all are gone!

Today it happened again and this time I took a screenshot before starting my course on the app.

I did my course on web but before refreshing the app I took screenshot.