Change desktop menu behaviour

I am developing a wordpress website and need to change the behaviour of the menu to improve the UX on desktops

here's the site: https://carrdalenew.carrdale.com/

There's no issue on mobile and tablets because swipe and tap doesn't trigger the js in the same way as desktops. Here's the issue for desktops:

The main menu appears on hover. The issue is that when you hover over a top level item the sub-menu items appear (this is good!), however, when you move to another top level item the sub-menu items scroll up and you have to move your mouse back to the item you require in order to open it (this is bad!).

I am looking for some help with javascript to change the behaviour so that the previously opened sub-menu remains open until you click on the next item you require.

To make this clear here's an example. Hover over 'our websites' > a drop down of the website categories appears. Now you want to look at 'website services' so you move your mouse to this menu item. The webiste categories disappear meaning you have to move your mouse again to click on 'website services'. The website categories should remain static until you click on your next selection. Just to be clear – if there is another drop down on your next selection this should appear on hover resulting in two sub-menus being visible until you click.

Please let me know if you need further clarification.