Dropdownlist works on chrome but not in firefox bcos of false mouseOut event in firefox

[givemeawhisky]

You might be better off doing something like this.
https://www.youtube.com/watch?v=HmTkf5af0NE
https://codequeen.wixsite.com/double-collapse

Or look at these examples.
https://www.wix.com/corvid/example/collapse-elements
https://www.wix.com/corvid/example/mega-menu