Hello,
2/ I have reuploaded all the files of the parent theme. Never edit the parent theme files. If you want to make any changes then use child theme for these purposes https://developer.wordpress.org/themes/advanced-topics/child-themes/ . Probably your edits caused the mentioned issue with the layout. So, use child theme and place your changes for the single product there. But be attentive because we are not responsible for issues that you have if they are caused by your custom code.
3) You used Elementor to create the submenu. It displays the styles for the elements for both desktop and mobile. So, I have added some custom CSS to apply styles different from the desktop style on the mobile device.
4) For me it looks this way https://prnt.sc/26et9n0 Clear the cache if it’s different for you.
Regards