Well i checked this issue on our local test setup and was able to replicate the issue .
I noticed that this issue appears when the event is loaded with the ajax call .
In the calendar view the events are not initially loaded in the page .It is loaded by making an ajax call when user jumps to a date and event is found on that date .
Now the issue is Visual composer is not ajax compatible .So it is not able to execute its shortcodes.
On your events directory page events are loaded when the page is loaded and here no ajax call is used to fetch the event content So visual composer works fine there .
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