I downloaded the latest plasma ISO from patreon (slightly less broken). I installed as normal, wiping the entire drive and selected the LVM encyption option during install. When I restarted the system wouldn't boot.
I tried again using legacy instead of UEFI and the same thing happened but instead of booting it went to grub rescue. I tried to access the hdd but it couldn't recognise the filesystem of the encrypted drive.
I then tried to install using UEFI again but with no encryption and everything went fine, it booted into Solus Plasma.