Sorry but we have not heard any issue with regards X and PressApps, in fact, this is the only thread will show if you search PressApps in the forum. Maybe that is a conflict with other plugin or a server-side issue. Regretfully, we cannot provide support for third-party plugins as our support policy in the sidebar states due to the fact that there is simply no way to account for all of the potential variables at play when using another developer's plugin. Because of this, any questions you have regarding setup, integration, or troubleshooting any piece of functionality that is not native to X will need to be directed to the original developer.
Please clarify what menu tab in wordpress you're referring to, I did check the Appearance > Menus and it seems to be fine.
I did check your child theme and it did not contain any WooCommerce template. Please update your WooCommerce to the latest supported version (3.5.1).
Remember to clear all your caching features (plugin, server-side, CDN, and browser's cache) after updating so that the code from the latest release is always in use. This will help you to avoid any potential errors.