The container containing your menu is invisibly covering the bottom bar with your search field because of its padding.
Currently, the said padding is 53px in all sides. Please set all padding to 0 and space out your logo and navigation inline correctly. What I mean by that is you utilize the Containers Flex Layout options which is essentially Flexbox features. You can learn more about Flexbox at https://theme.co/apex/forum/t/using-flexbox/24851
Please watch the screencast below for my recommendation.
To help you know the better option to use between margin and padding, I'd also recommend that the Margin vs Padding article at https://uxengineer.com/padding-vs-margin/