Mine wobbles too, got under it to figure out where the wobble was coming from, and rather than from the metal base, the wobble was in the arm attachments. Looked closer with a flashlight and discovered that the support boards for the arms have all completely given away and cracked free of their nails. We've only owned the item for FOUR months. I'm so ticked off.
Lynn
February 2017
Clearly the fixing screws are working lose - that explains the wobble and the squeaking.
Invert the chair and examine the underside - ask a friend or neighbour to do it if it's too big a job for you.
Examination - diagnosis - repair is what you need to do
Nobody here can see what's going on with the chair.