I am testing a new STXL-11002 and seeing a strong vertical grad. Images are about 500ADU brighter at the bottom than the top, for both Dark and Light frames, and binning at 1x1 and 2x2. I am also seeing vertical banding, which I can see from another post is to be expected with this chip. It looks like the grad can be corrected out as well, but is that also expected for this camera? Sample image attached.
Yes, that solves it. I didn't think to try the cooler because I was in the middle of trying to debug my autoguider problem, and I am used to the STT-8300, which is flat even when not cooled.