When adding a new product, The child product tab is automatically selected. Instead of the child product being at the bottom of the Prod info tab, It is the customfields tab with just one field being repeated. Is there a way to delete this? I am using VM 3.4.2, Joomla 3.9.6, and PHP 7.2.
Your post is very confusing, because the title indicates that you write about deleting a child, but then you write about adding a new product.
First, when you add a new product, you see in the URL that the product id is 0. A new product has no id as long it is not stored and so it makes not really sense to show the "add child product". it would implicate that the product must be stored first. It could be written that way, but then user may wonder that it stores and creates a child.
The cf table thing,.. I dont know, it depends on the parent. It should show the customfields of the parent, not more. But be aware there is no generation limit (even not displayed in BE, but in FE!).