Cannot edit old daily data

I noticed a few months ago that the Android app was no longer scaling correctly. The Y-axis has a much too large scale. Now I looked into the matter and found that on July 6th, 2025, some data was not transferred or was transferred incorrectly. As a result, the average value was calculated much too high. Unfortunately, I can no longer correct this. Even deleting this day and entering the values as the sum for the day did not help. How can I correct this?