-I have a 500 GB SSD with a CentOS build on it (legacy boot).
-I'm trying to also install Neon on that drive from a live usb install drive.
-I choose to manually configure the partitions.
-But while there's over 400 GB of free space, the buttons for 'add' don't do anything.
-IF I select the free space button in the middle of the partition map, I get a new partition window.
-BUT, while I can create a root partition, the rest of the free space becomes unuseable (? was that the term).
-And I can't create the other partitions.

Any help most welcome.