I just took 4 pictures and looking the details for each one I found the following:
3:4 - 4032 x 1908 (results in 6 M)
9:19 - 3024 x 3024 (results in 9 M)
1:1 - 4032 x 2268 (results in 8 M)
Full - 4032 x 3024 (results in 12 M)
So, my results are very different from the ones mentioned by...