Dropdown doesn't work on Menu

Hello,
I’m fairly new to wordpress, so I might be missing some key elements with designing my new website.
At first, I started my editing without created a child theme. but only after a while a friend told me that it’s preferable to do the editing on a child theme, so I went and created one.
After working a bit on the child theme, I noticed my menu dropdown no longer works when viewing my site directly, oddly enough – it does work when I enter the customizer and hover over the “Shop” menu item.

I have no idea what i’m doing wrong here, is it possible that the changes I did to the “Mother” theme is interfering with the child ?

Thanks !