Yesterday I made a session with my 550D and when I did the darks right after the lights, the capture would return the last light image on all darks!
I had to shut down indi server and restart. Using RPi server and Macbook client.
No logs avalaible, I will try next time.

And the same as just happened with linux client, made 20 darks and when switched to ligths, all are the same as darks.

I know how you feel..... frustrated right? I also experienced this recently. Very annoying!

But my case is a bit different For an example, after I finished M42 capturing schedule, normally i will load another schedule for my next capturing session let say M45. But when I start my M45 capturing, the first image that I get is M42 and so on........... AAAArrrrrggghhhhhhhh

yes, just like you said, completely frustrated. It's very annoying indeed.
It also happens between different schedules as stated.