Different font sizes all of a sudden??

I am so frustrated and hope I can explain what’s going on with my blog.

When I type a blog post lately, in the editor, I end up with 2 different size fonts. I will have one sentence/paragraph in one font size, and the very next sentence/paragraph, will be a larger font. No matter what I do I cannot correct this.

I’ve tried logging out and back in, deleting photos I’ve inserted into the post, deleting and then retyping bulleted text, etc. Everything I can think of. For the past few blog posts I have literally had to go back in to the editor, retype a paragraph, delete the text that ended up in the large font, save the draft, and then do the same to the next paragraph.

Needless to say, I am so frustrated. I’m running 3.8.1. and I’m not even sure if this started happening when I upgraded to this version or not to be honest. My blog posts look ridiculous now.

Is anyone else having this issue? Here is the link to my last post. I just gave up trying to correct the issue. If you scroll down you’ll see how the font size gets larger and then smaller and then larger again.

https://royalicingdiaries.com/?s=swim+team+cookies

I thought it was a theme issue but my theme developer has been trying to figure it out as well and, like me, thinks it’s an issue in the editor.

Any help would really be appreciated.