All right. Now that I know what you are looking at, I understand your confusion. I believe what you are experiencing has nothing to do with the fact that you started charging VAT.
I believe you must have updated your software around the same time.
Manager recently underwent some changes to how inventory items are displayed, because many people were using the item name and item code in ways that were not intended. The item code is meant as a search and organization aid. The item name is meant as a shorthand way of searching for something. For example, you might put a model number there. All substantive information about the inventory item should go into the description field, which can handle large amounts of text.
So places where those three fields are displayed were changed. Many reports now show the description only. Item names no longer appear on sales invoices, for example, even though they are visible when creating the invoice.
The tax heading now appears because you started using it. Many columns on Manager reports disappear if they are empty.
I return to the third question in my first response: what are you trying to accomplish? There is probably a way to obtain the information from Manager. For example, have you looked at the various inventory reports? Since you seem to regard the inventory item name as important, I wonder why you are drilling down on the inventory sales account when there are special reports about inventory.