Color of the selected top level menu item

Hi!

When I hover over the top-level menu item it changes bg-color to what I choose in settings. But when I move the cursor to appeared mega-panel or flyout menu the bg-color of the top-level item changes back to the primary one. With a mega-panel this leads to lose of visual link to the top-level item which this mega-panel belongs.
I wonder how can I make the top-level item keep the ‘hover’-bg-color while I move the cursor over the mega-panel or flyuot menu.

Site: https://alexbr.ru/oldhamgas/

https://www.ads-software.com/plugins/megamenu/