Earlier stylesheet not overriding later one

I looked at my child theme’s functions.php and I found that I had commented out the line to enqueue the child style.css. I’m guessing that the stylesheet is loaded automatically because that is the active theme. I would suggest you try not explicitly loading your child theme’s stylesheet and see if that helps.

P.S. Only include the styles in your child stylesheet that need to be overridden. In other words, at this point, you should only have styles for h1, h2, h3, et al.