I tried that and that got the same result.
To make sure there wasn't something funny about the text itself that was causing this, I tried copying some plain text from TextEdit (just the word "Hello") into an "Insert styled text by pasting" action. I got the same result—-the text was doubled.
I just tried uploading this macro, but it went here instead of into this post (if you have admin privileges, feel free to delete that post and move the macro here):