Hi,
The mega menu settings does not save the configuration. When I set up the columns and add modules items in the menu, save, and then return again, the mega menu is disabled and when re-enabled, none of the columns or modules are there. Please see this in action here:
https://www.loom.com/share/8a01bd5cb08844e4ac472492035b2cde
I had asked about this in another post here: https://www.joomshaper.com/forum/question/8277 But the suggested resolution did not work. This time around, there's really nothing special running on the site: https://monosnap.com/file/19UxTCPS2acKf8gw0nALtQxNKup4UP
The site is in development and behind a password protected directory. Let me know if you need access.