So it does the same thing as the Panasonic. Adjust it back to 0 and give that a try to see if you now get a decent or overexposed image. If it is overexposed you can then turn it down again in say -1 steps and -1/3 steps to get rid of the overexposed parts of the moon. But also check that you are using either spot or center weighted metering. Otherwise the dark sky around the moon is going to cause your exposure value grieve.I was using my Fujifilm X-T30. Exposure comp. shows -5 when in manual.