Greg
Ancient post here, but my system started having the exact same problem around Dec 23 2020.
Did you ever resolve this?
I use TSX as my imaging platform using Ascom driver, and I process using Demetra LISA. I have a LISA + ATIK414EX (and 460EX) M.
The problem I was seeing is the images of the spectra look fantastic. Prior to calibration.
When I did calibration the spectra was not useable. Normally I apply 17 darks and 25 flats. This had been working no problem from April last year to December. But in December, started getting these really weird results almost like my dark frames were not good (e.g., background on a calibrated image became mostly white, and spectra was barely visible, and on calibration lamp, prior to processing many lines seen, but after, only 2 or 3.
So I started playing around. Found that if I replaced current darks and bias' with darks taken in November or earlier, it came out normal. But cannot use those as they are out of date.
Sadly I have been futzing with this since mid December. Using Demetra, CCDStack, Isis, it is the images not the processing tool.
Just today saw that my drivers for Atik were quite out of date. There had been 2 updates since my load last year. So just downloaded the driver and will reshoot Darks and Bias and see what happens. I can only guess that when I updated the ASCOM platform to the new 6.2x something changed and that is where my problems began.
Thanks
Keith