Details Window Closes Automatically on Mobile

My site isn’t live yet, but the calendar on mobile is giving me issues. Clicking on the day, it opens the details window, but if I scroll to high or low the window closes automatically. Then if I try to click on the same day to view the details again, the window will not open. I have to refresh the page to look at it again.

The page I need help with: [log in to see the link]