Please check this link
http://prnt.sc/c6x3va
Also This Link in full view.
http://prnt.sc/c6x568
Try giving the mega menu width in pixels, it should resolve the issue.
Try clearing browse cache and if you're using any caching plugin with minified files, try clearing the minified file cache as well.
example : http://themes.vibethemes.com/wplms/skins/demo1/
The demo mega menu has width 560px and the other mega menu has width 100%.
@safetyskillsltd : I would request you to create a new topic for this issue as it is not at all related to the topic title.
Please help us in keeping things simple and organized :)
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