Hi @Anonymous ,
I would suggest you recreate the form and the date picker field to see if the issue is fixed since there is no way to adjust the calendar location.
If it still doesn't work, please try this alternative workaround: https://powerusers.microsoft.com/t5/Building-Power-Apps/Action-on-datepicker-when-the-calendar-shows/td-p/539285
To create a custom date picker/Calendar control by a TextInput box, Calendar icon, and a calendar component.
1. add a TextInputbox and a Calendar icon inside the Card, add a Calendar component and OK/Cancel button outside the Form.
2. set Text box.Default: Calendar_1.StartDate
3. set icon. OnSelect: Set(MyVar,true);Set(selectedDate,Calendar_1.StartDate)
4. set Calendar_1.SelectRange to false
5. set OK Button.OnSelect: Set(MyVar,false)
6. set Cancel Button.OnSelect: Reset(Calendar_1);Set(MyVar,false)
7. group Calendar, OK button and Cancel button, set Visible propert to MyVar
8. set DataCard.Update to DateTimeValue(TextInput1.Text)
Demo:

Hope this helps.
Sik