I started a PhD 8 months ago as part of a funded project and after courses, my first seminar, and submitting one paper, I am absolutely certain this project and this research group is 100% not for me. I found a few other PhD project at different universities that I am sure are a way better fit. In my application/cover letters for new positions, do I mention that I have already started a PhD? I came to my current program with ~5 years of work experience - not sure if that makes a difference.