All PVS-14's suffer from this to some extent. It's caused by a combination of factors, but if you want to record it simply, mount a video camera on a tripod and show it the same scene through the monocular. Turn the monocular around while viewing the scene.
Now review the tape, and place a dot of paper or something on the screen near an easily distinguished feature, like a corner of something. As the monocular moves around, you can see how far the optics move it away from the orginal scene.
This is what you're experiencing and if it didn't occur, you could use your PVS-14 as a clip-on aiming device in front of a dayscope.
As for internally? There's no correction. If the tube is a little skewed or potted slightly off-axis, it can exacerbate the issue. If it has distortion, that can make things worse too. Looking through the edge of the ocular lens is also likely to make things worse.
About all you can do to fix it is to make sure the tube is seated properly. There's no adjustment that will fix it. If it's really bad, or it's bothering you, call TNVC, and send it back. They are good guys and will fix it if it's a serious problem.
But otherwise, using your unaided eye and the monocular at the same time? The issue will always be there. It's common to all monoculars. Short of installing something like a risely prism in them, there's nothing you can do either.
Though on that matter, it is possible to install a risely prism in the ocular if you do end up with a severe enough problem. But custom optics would be very expensive.
Regards
David