Hi Nuno,
Sorry for the inconvenience.
The reported issue “DatePicker value becomes null when model value is binded” is already a known issue at our end and also we have fixed this issue with our patch release that has been released today (3rd July 2018). So, please make use of the update scripts (CSS and Source files) to resolve this issue at your end.
If still any persist at your end, then please revert back to us with more information so that we can provide an exact solution for your requirement.
Regards,
Prem Kumar M