[تم الحل] Delete / reset all menus due to strange problems

Background of the issue:
I am trying to display Overlay panels to create a mega menu with display rules that determine the language on my site الرابط المخفي. I want the Dutch panels to show only in Dutch, and English panels when visitor visits /en/, but they are not working as expected.

Symptoms:
When I select 'show only on Dutch', I get no panels, and only English versions show. I tried all kind of settings and combinations but it's not working as expected. I suspect there is some history left in the menus.

Questions:
How can I delete the Dutch and English menus completely?
How can I remove WPML entries if necessary?