Post sequence break using BB code

Affected version
XenForo 2.2.9

I'm able to break all content following a sequence-breaking post out of the main container using the following BB code:


The first post, "Test", is the sequence-breaking post containing the aforementioned BB code.
The "Test reply" post is a reply that is now outside of the main container instead of being below the first post.
Additionally, the reply box now spans the entire width of the viewport.

Tested using a fresh vanilla XenForo installation using Chrome, Safari, and Firefox on macOS Monterey.

Please let me know if I can provide any more details. Thanks!