Goodman and this is the answer their technical advisor gave us. It is with txvs also. I have seen it with my own two eyes and yes I did check to make sure indoor conditions were the same. At install sh correct, two weeks later severely overcharged, not just a little. Maybe its not the refrigerant, maybe its something else that changes, all I know is that once we started weighing the charge in at install the problem went away. Just like goodmans rep said, so I had no reason to doubt him or research it further. I absolutely hate the idea that the direct measurements are inaccurate, but that's what works. I know a lot of guys on here install Goodman equipment, we can't be the only company that's had this problem