I found the solution to this and it’s very easy! π
Just go to menus and add new link instead of a new page. When you have added it to the menu delete the url and set the navigation label to the text you want to show in the menu. Then adjust the position so that this link becomes the parent menu you want.
Glad you found a solution!
Rather than a blank link, adding the character # in the URL field is a bit better. While neither option is generally recommended – it’s better for usability, SEO, and accessibility to create a “landing” page for the parent item instead of an unclickable menu item – adding the # character at least preserves some of the functionality of a regular parent menu item, especially on mobile devices.