I've tried a dual boot configuration on a MacBook Pro 2015 with the help of ReFind. I installed GNOME with Mojave. Whatever it is, after a few restarts, Mojave has stopped appearing at startup. I deleted the GNOME partition and reinstalled Mojave.
However, my old 250GB SSD hard drive now appears under Disk Utility:
The diskutil list gives me the following information
Can any one give me an idea about how to progress? Ideally, I would also like to recover data on the "lost" installation of Mojave, if possible. Thank you!