There are a couple of things going on, I believe.

First, the extra numbers tell me that you likely have numbering applied to your TOC style for that level. That needs to be removed.

The second is the placement of the tab settings in the TOC style. You need to move the first tab stop enough to the right to allow for the number.

See TOC Tips and Tricks - Modify TOC Styles by Suzanne Barnhill, MVP.