Start a new thread as normal and click on the Code button to insert the code as follows:
Then click in the editor window to continue composing the post and the next key press, e.g. Enter, results in this:
A CTRL+Z brings the text back and then the next key press moves the focus to the top of the editor window so the cursor has to be placed back at the end of the inserted code to continue writing the post.
This happens pretty much every time.