Applying a custom tag to a piece of text removes existing tags from it.

For example, in an article puts the text "Tags are removed from the text when applying a custom tags." and put "removed" in bold", "text" in italic and add a link on "applying". Then try to strike all the sentence, bold tag, italic tag and the link are gone. The same occurs with a block custom tags like quote.

If you first apply the custom tag and then put a word in bold, italic or add a link, it works well.