If I hide said dropdown, the whole nav bar (including burger icon and branding logo) vanishes.
Any help on this would be appreciated (this is work in progress, so I am still adjusting the tablet view so please bare with!)
You need to ensure the menu button is not a child element of Nav Menu which is what shows & hides (along with all child elements). Drag Menu Button above Nav Menu to be inline with the navbar Container and adjust position settings from there.
