My date formats generally appear correctly, however if I create a custom field with the Date Picker (not the date/time picker) the date will show correctly in the form, but when this text is added to the issue, it is the incorrect format.
For example, it shows as May 5, 2020 in the form after selecting this date. In the issue that is created it is formatted as 2020/5/5.
I have no date formats which match YYYY/m/d or anything formatted to have the year first.