Here's an excerpt from the V7 User Manual:

"Always keep level ( ): if toggled, this option instructs Vue 7 to make sure that the camera is
always horizontal, resulting in a horizontal horizon. If (and only if) you deselect this option, you
can add roll to the camera. This can energize pictures on occasion. However, for general purposes, we recommend that you leave this option on."

So it would appear this behavior is as intended.