How to fix text style in table of contents?

Question

Word

There is a word document.
I go through the document, and where the section/subsection title should be in the table of contents, I highlight this section title, then go to the Links tab -> Add text -> Level x. Also a few
When I then insert an auto-generated table of contents, 2 problems appear:
1. Some fields pop out to the left of the table of contents
2. Some fields are bold, and some are not, although all but one of them are bold in the text itself.
Why did these problems appear and how to fix them?
Here is a link to a piece of the document: https://yadi.sk/i/WE6n-J8Ks3acnQ