After signing up to a new ISP, I was prompted to sign into my Creative Cloud account for the first time in several months. My Rush project did not appear so I followed common Community advice and signed out and in again, still with no success. I was close to panic as I have only the desktop version and therefore did not have a synced copy of my project on any other device. I quickly solved this issue myself after realising that I had connected an alternative little-used email address to the CC account, and of course, when I signed in with that email my project appeared safe and sound. Silly mistake.