We are using the InPlaceEditor for DateTime inputs. At the moment we can change the date time formatting for the DateTimePicker, but when we set an initial value for the InPlaceEditor, the date time format is not the same.
We did some research and we found that this is because the initial parsing is done using a fixed format 'yMd' and 'hm' (see attachment).
Also you can check a reproducer test here
The initial format is not consistent with the custom format.