Daily quota is incorrectly calculated

since update of new app version ,
the calculation of Daily Quota in my (unchanged)
data plan is wrong. It counts one day too few.
E.g. I have a data plan starting 18.3. lasting 14 days. Which means this morning there are 3 days left: 29.-31.3.
Remaining data are 600. should be 200 per day. but the app says 300 per day.
Similar deviations I saw in the days before.

In earlyer App version this bug was not there, with the same data plan.

thanks for help