Full Menu Display Flashes on load/refresh

[etherplain]

I don't think this is the same issue described before as #4 Firefox flashing issue, but it sounds similar. Regardless I'm using the latest rendition of the code. I've run it in Chrome and Firefox and while Firefox is much worse, there is still a flicker even in Chrome where you see the whole branch of the hidden menu before is collapses into the mega-menu CSS display settings. Is just my testing environment or do others experience this? Any ideas in either case?

[etherplain]

I found the solution to this elsewhere. Not sure why it's not been added to the source code though.

It's discussed here, among other places: https://stackoverflow.com/questions/46654441/mega-menu-flashing-on-page-load