Position of the calendar popup is off the viewport

The issue https://github.com/amsul/pickadate.js/issues/491 relate to the classic theme. I have similar issue with the default theme. See picture:

I have a long list of items with a pick-a-date field in them. If I focus on the date field in the bottom of the list, then calendar popup show partially of if the list is too long it doesn't show at all. However, is focus on the date field of an item that is at the start of the list, them the popup show properly. What is the best approach to solve this?

Thanks