Are your Flats Overcorrecting?
Are your Flats suddenly overcorrecting your Light images? This just happened to me, and I found the problem and corrected it.
Maybe my experience here could help you with your problem!
Overcoming Barriers: Flat Calibration Frames
There are many barriers to overcome in astrophotography. This is a post in a series addressing how I overcame those barriers. For this article, I discuss doing flat calibration frames. More specifically, how do you get a good light source that is appropriate, reliable, and repeatable? This shows how a $20 LED Tracing Panel could be used for this purpose.