Brand new out of the box chipped and dented lid rim is a good indication that the box got dropped on the side. Good chance the bowl is also out of round. I have seen both new and used kettles with this issue and have been able to resolve the problem in most cases. Use a good round bowl and a lid as a guide. Also, good level flat surface to see if it rocks as you have already tried, and measuring tape to check roundness is very important.