I just received my ASI2600MM and it shows a marked horizontal banding. It happens at every exposure/gain.
The banding is just random and it changes at every exposure, so unlikely to calibrate out. It looks like an old TV
I have tried the followings without success: various USB cables, various power sources, different computer, power plug, USB traffic, multiple software (NINA, ASIstudio and Sharpcap )
I have uploaded here fits files and two screen recorded videos that clearly show the issue