month-stepper broken in date field in Safari 10.11

hello again

a client reports this error in Safari:
Date-field > calendar-popup > changing the month does not reflect in the date field after popup ist closed.

To reproduce:
1) Backend
2) create new item containing a date field.
3) in the date field, click on calendar-icon. calendar-popup appears.
4) in the calendar-popup, in top area, click on left-arrow-icon or right-arrow-icon next to month to change month.

expected behaviour: month changes.
real behaviour: month does not change.

Flexicontent 3.2.1.9
Joomla! 3.8.3
Safari 10.11
Mac OS

Thank you!
Kath

Hello

we are using the Joomla built-in calender

so it sounds like a issue with build-in calendar
can you also test in non-flexicontent forms ?