Text Editor / Container has issues w/ Text Formatting

Issue w/ Text using Underline format for text. Text will display fine in the text editor, upon posting this text is omitted from the post

Steps:

1. Create text content either in the text container, or externally + copy & paste.
2. Use "Ctrl + U" to start underlining text format
3. Create text with underline
4. Click submit new topic

Result: Text omitted from post

Expected Result: Text appears as formatted in text editor

Also unexpected, the Underline text formatting option does not appear in the text editor as a clickable object

Also, Jeff, the text below this line is underlined, and doesn't appear. Not sure if that'll help find what's being removed: