[Plugin: Events Manager] Date Picker off screen

Interesting problem here with the Date Picker.
See this screen grab

When the upper right date field is clicked the calendar displays below it which is OK.

However when the lower left field is clicked the calendar decides to appear above like this

and when this happens if you click in the part of the calendar in the Header area it just closes so it’s impossible to select a Month or Year.

Where the picker appears is not consistent because sometimes it appears in the upper position from the upper right field ?

Is there any way to control where it appears ?
OR
What governs where it appears and how could we teach it not to do this ?