Menu on Mobile Covers Header and is the wrong color - Sense Theme

The menu on my store keeps covering the header when on mobile. I’ve tried all the settings I can think of to correct it, but can’t get it worked out.

I’m using a modified Sense theme 8 (I used it for a previous store and uploaded it to my current store). I got the menu to work how I want to by downloading the default Sense theme, but I can’t figure out what settings to change in the theme I’m currently using. My store is almost complete and this is the last thing I want to sort out. Short of modifying the default Sense theme to look like my current store, how can I fix this???

I’ve attached screenshots showing what it looks like, and how I want it to look.

I can’t get into developer tools on mobile.

I’m glad you have experience, but that does absolutely nothing for me.

UPDATE: I was able to open the code for the Sense theme and my store theme. I copied all of the code from component-list-menu.css, component-mega-menu.css, and component-menu-drawer.css and pasted into my store’s theme.

HOWEVER - the background color of the menu is still black - and not white, and the social media icons at the bottom of the menu are skewed (half of the FB icon is cut off).

Not sure what’s causing either of these issues as I literally copied and pasted.

I copied the entire content from all 3 files… there’s no way it wss copied incorrectly.