Reply To: Fixing unwanted changes after updating from 4.6.0 to 6.0.3

1. The font-size of the main menu items was changed via custom code on your live site. To make same changes on dev site try to change following custom code from
.main-nav .item-level-0 > a{font-size:14px;}
to the
.wd-header-main-nav .item-level-0 > a {font-size:14px;}

Following code also is located in your child theme style.css

2. Spacing between menu items can be changed via following custom code:

.wd-header-main-nav .item-level-0 > a{
	padding-left: 12px;
	padding-right: 12px;
}

Kind Regards