Just installed an American Standard Cadet 3 based on some pretty good reviews from this site. Seems to work fine, but I do notice that the tank seems to rock a little. What I mean is it does not seem solid. I can grab the tank and push it forward and back unlike the other toilet I have in my basement that is very sold and does not move at all. Both have a 2†space between the tank and the wall behind. Went to my parents house and theirs is solid as well. The bolts connecting the two are very tight. It’s to the point that I’m afraid if it tighten too much further it will crack the porcelain. Is this the way this model is supposed to be?