Rincoe mechman; loose 510 connector issue? Or is mine just off?

I recently.got the mechman, and it functions fine. However, the 510 connector seems to wobble back and forth when I screw a smaller tank on to it. All of the connections are fine and it functions as it should, but it is noticeably raised a bit when you look closely. Pressing one side down seems to push the other up. Oddly enough I only really notice this with a small tank screwed in. Otherwise, it looks pretty flush when nothing is on it.

Is anyone else experiencing this, or is this just a one off fault with my particular device? I'm not too worried about it, but I am curious nonetheless as I notice it when I throw my Zenith tank on there.