Fix responsiveness issue - jQuery & CSS - WordPress/Elementor

See site navvi.uk
If you resize the window you will see the issue I have with the side menu.
On desktops and mobile the layout is fine however on tablets the layout tries to collapse to a narrow version of the menu which breaks the layout. I want the mobile layout to apply in portrait tablet mode instead of the collapsed menu.
The site is built using Elementor and all the custom css is attached to the individual elements. The JQuery code is in an HTML code widget on the menu.

Also - the page is a one page design and the menu links to the various sections. On desktops, clicking a menu item scrolls the page down to that item, but it doesn't align it with the top of the page. Instead the section starts half way down the page. Can you also edit the code so that when a menu item is clicked, it scrolls the section right to the top.

Looking to get this completed ASAP so please let me know when you are available to complete.

I have attached a video showing the issues that need fixing.