Even though Track Changes is turned off, marked revisions are still in the document.
In case you wondered, turning Track Changes off does not delete tracked changes (or comments).
Here's what it does do: All tracked changes already made up to that point remain in your document, even though Track Changes is turned off. Any revisions you go on to make will not be marked as revisions.
To remove tracked changes, you accept or reject them. To remove comments, you delete them. You'll see how to do that next.