Reduced Test Case

https://codepen.io/bopm/pen/MWPerQw

Do you understand that if a reduced test case is not provided, we will intentionally delay triaging of your ticket?

• I understand

Which connector are you using (React/Angular/etc)?

No connector (vanilla JS)

Bug Description

Providing validRange to limit months available for display in multiMonthYear leading to

typeError: Cannot read properties of null (reading 'start')
    at rangeContainsMarker

and failure to load the calendar.