changing size of heading 1 messes up

I go to styles. It says 130%. Everytime I work with a doc with percentages I get mixed sizes. So I change that to 10pt. I don’t want a 10pt heading in the long run, but I want to see it change. The first heading in the document remains unchanged. The second first level heading in the document changes half way across. The first 12 letters are at 130% while the last 12 are at 10pt. All on one line. The cursor is at the top of the page, but that shouldn’t matter, as I’m changing the style on the styles menu, it should apply to all of the H1s.

How can I change the heading size from percent back to point?

Looks like your heading paragraphs have some manual formatting over the style? Thy Format->Clear Direct Formatting.