It's probably just the script for the nested tag. It was so inconsistent with the tags it worked with when I was adding random things to my test layout.
Half the time, it would nest, but the tag wouldn't be there even after adding it to a random post. The other half of the time, the tag would show up, but the nesting wouldn't. It seemed to be having a harder time doing the longer tags properly, but there was no reliable length I could shorten them to in order to get them to show up all the time.