Create a Navigation Bar Link to a Portfolio Project Sub-Page

Hey there! I've just created a new 7.1 site, and I've encountered a frustrating problem. I'm trying to make a link to a portfolio sub-page that would appear in the main navigation bar. However, when I try to make a new link to facilitate this, I can not enter the sub-page's full url into the link configurator. I'll try to type "/landing-page/design" with "landing-page" being the portfolio and "design" being the sub-page, but the site straight up refuses to let me type the second / in the address. is there any way to get around this? Thanks for the help.

Hi. have you tried enter full url yet, something like this: yourdomain.com/landing-page/design?

I have also encountered that problem. It is frustrating that you cannot link a project. Why is that even the case?