Air bubble in J-stik

[D5A1AC]

I bought two ball top J-stiks a month or so ago and they seem to have air bubbles in the handles of them. They were like this when I got them but I never got around to asking about it. On one of the joysticks the air bubble has  spread somewhat. Both joysticks have seams around the equator of the handle which are easy to feel and fairly visible. I've attached a photo of the air bubble in one of the joysticks. They are both on the top of the handle. Is this the norm for J-stiks? I bought mine from Oz-stick.  For just over 20 bucks a piece, I had not expected the joystics to show any signs of cheap manufacturing.

On the picture, the camera flash has exaggerated the air bubble somewhat. It isn't really THAT bad in real life, but it was visible enough that someone said the joysticks had "nipples".