Shelf keeps slanting

Hi everyone! Every time I use the shelf, it starts slanting in the oven! I check every time and it's not caught on anything and the pizza is evenly in the center. Just one corner is about an inch off the rack! What's going on??

If it doesn't slant on your kitchen cabinet and just on your oven shelf then check or swap the shelf in your oven. If it slants only when the oven comes up to temp then try preheating the oven a little long 5-10 minutes and or extend the broiler warm up time. Another alternative would be to lower your shelf a tad away from the broiler.