Help needed with navigation menu not working on mobile devices

Hi! So, we're having an issue with the site navigation menu not working on mobile devices. The menu appears but some of our drop-down options don't appear. Here is a link to the site: www.birthandbeauty.com The "Portfolio" and "Services" menus have custom links as drop-down menu options and they simply don't appear, at all, on mobile devices. On a traditional computer, the menus behave correctly. Any ideas on what could be the issue? We're running Photofocus Pro 5.1.7 on Wordpress 5.7.2, running on PHP 8. Thanks in advance!