After a looong while I tested my equipment again and all is working fine! I recently got a Lodestar X2 and it's so fast that I can loop the camera (using the option in the guide-module) to focus my guidescope which is great, but then I started to do a polar alignment process (using EKOS) and I noticed that the guide-module kept on taking over control and started looping again, preventing the polar alignment process to receive an image. Restarting Kstars solved the issue so I guess it's a bug.
edit: to be sure, I pressed stop in the guide-module to stop the looping, before I went to do the polar alignment.