Cause: When Pre-order Now is included in the theme, the JS code that controls the dropdown / mobile menu in Venture theme's theme.js file runs before the page is fully loaded. This breaks the menu.
Solution: Put the contents of Venture theme's theme.js file in a jQuery ready block so it runs only once the page is loaded.
Example:
$( document ).ready(function() {
//theme.js code goes in here
});
Steps to implement the solution:
1. Navigate to Sales Channel -> Online Store -> Themes.
2. Click on the three dots for the desired theme.
3. Select "Edit Code."
4. Expand the "Asset" folder then click the theme.js.
5. Insert the code "$( document ).ready(function() {" before the /* ================ SLATE ================ */
6. Scroll to the bottom of the file.
7. Add the code "});" after the line "$(theme.init);"
8. Click the 'Save' button to apply the changes.