Ok, let me try to explain how I fixed my wobbles from my filco tkl. I picked it up and put my palms on the upper right, and bottom left corners. I put my fingers toward the back and pushed my fingers toward me. Almost a twisting motion. It popped like the case was popping together. I think it got banged around during shipment, but yeah, it hasn't done it since. If that doesn't work, try the same action/motion on the upper left and bottom right corners. I can take some pics holding mine if this doesn't make any sense haha
Editing in a picture. Couldn't exactly pick it up, and take a pic while holding this dslr xD
Use your palm to hold it in place, and apply pressure with your hands on the backside. Both hands at the same time toward you. Not too much pressure. Try this, sit it down and see if the wobble is worse or better. If it's worse. Switch corners.