initial cycle length help.

Robin • Mommy to Phoenix 8.8.19 my beautiful rainbow baby boy!

when I put I have a 28-day cycle, it changes my current cycle to 36 days. I don't understand if I'm doing something wrong. I should be getting my expected period on February 2nd and now it's estimating February 8th. if I change my cycle to 24 days it's closer January 30th but I still can't seem to get it on February 2nd on the app. Any help would be greatly appreciated