Until you get the gain adjusted properly you're going to see one of two results from the InAmp; either ~2V or ~4V.
If it's sitting at the ~2V value then your gain is too low. If it's at the ~4V value then the gain is too high. Keep playing with the gain until you get something in between, then decrease it a few ohms until it shows ~2V... and then you're ready to test it by pushing on the load cell.