[NSFW] Deleted menu options still shown

Hi,

I recently added Mega Max, and added 1 menu option (What I Offer) where I use it as Mega Menu – Standard Layout. Works fine.

But in the management of the menu strange things happen.

I added an extra login option to the main menu. I did that, because the current login option no longer used the login mask. After saving, both login options apply the login mask. So I deleted the one just added. It’s out of the main menu under Appearance, but it remains visible in the front end. Whatever I try, it seems that changes to the menu no longer get reflected in the front end.

Cleared cache on server, in the browsers, used different browsers, private windows. I see different versions of the same menu all over the place.
I think I’m missing something fundametally of the concept.
How can this happen, and more important: how to avoid?

The page I need help with: [log in to see the link]