I have the same problem since I updated the WP version. . I resampled the permalink and checked the Visual Composer roles but the problem remains, it does not find the portfolio page and displays error 404
We are sorry for the issues, you can try to follow this screenshot: https://prnt.sc/j8sf2g
But we don’t sure that’s fine. This maybe conflict issues, that is reason why we need to check your site then fix it.