G9X-II samples from photographyblog all have Black Level about 2047-2050. Do you use some special mode (noise reduction??) on your camera?
UPD: also, these files do not show 'one of 4' histogram even for higher ISO (3200-6400-12800). Unfortunately, no samples with intermediate ISO (2000) in this site.
Followup #3:
G9X-II samples from photographyblog all have Black Level about 2047-2050. Do you use some special mode (noise reduction??) on your camera?
UPD: also, these files do not show 'one of 4' histogram even for higher ISO (3200-6400-12800). Unfortunately, no samples with intermediate ISO (2000) in this site.