This I think was a first here. As far as I'm aware this problem has only been related to slanted apostrophes, slanted quotation marks, and long dashes. But here it seemed somehow related to ordinary letters, although it's hard to figure out exactly which ones. Looked like some of the vowels.
Below is an example of both types of apostrophes and quotation marks in a pre-post composition AND the result after posting or previewing both: