Maybe I'm pixel peeping too much, but if I debayer and stretch in PI, I see a very odd pattern in my ASI2600MC darks. It's quite unlike what I've seen others shared. Attached is a debayer with both a combined and separate RGB layers. Only the grey looks reasonably uniform. Obviously a dark will have some minor random gradients but this seemed quiet severe. Tried varying gain and also sticking in completely dark box, but those made no change. Also can't see any obvious marks or leaks on the sensor. A NINA auto stretch in Image mode doesn't show this pattern, but I guess it is a more rapid/approximate method than in PI.
Happy if this is not abnormal - but it's a new cam, so a bit concerned I may have a fault