Small issue on a webform (datepicker)

Hi all

I have a small issue on a webform with two datepickers.

Current situation:
The datepickers can be normally selected by pressing the "TAB" button from the previous field.
However when a mouse is used to click directly into the datepicker, then it shows up quickly and disapprears right away, not allowing the user to select a date.

Desired situation:
- The datepicker can be opened either by pressing tab from the previous field or by selecting it directly by mouse.
- Should work on all common web browsers

Required skills:
- HTML
- JQUERY
- CSS
- (PHP)

Webform link:
https://bahrain.helveticor.ch/