Search for tags with negation on name

I have success in using negation operator on name (name: ! string ) in search field and smart group for general item search but got some strange results when combining with tag search (kind: tags). The search results is a list of items which predominantly are not tags. Not sure what I have done wrong?

Are you actually trying to search for a Tag not named Apple?

Yes. But “Apple” is just an example in this case. Or this

Why are you using the negate option instead of is not here?

Ah, I see what you are asking. Coz I first test the negation operator in the search field for general item search by using name:! something.
Then I want to try searching for tags that doesn’t have a certain string in the tag names. I first tried “is not”. “is not” works for exact name but doesn’t work for partial match - with or without wildcard. So, I tried using negation. I also want to use use negation for “does not begins with” but not successful either. I read through the help pn search prefix.