Tab Groups don't work

I think I could really use Tab Groups, but they don't work. I've tried several ways of using them.

• The web sites lock and you can't open them.
• I can't delete one site from the over view. It does not delete the one I want to delete. It picks another one and deletes that.
• Sometimes the tabs in the group just disapear
• Often the over view just doesn't work.
• I can't add sites to an already existing Tab Group. Just won't do it.

Be nice if we could get this unfunctional feature off Safari and go back to the old format.