The problem with new installer seems to be that it doesn't create any subvolumes. It was the same issue with 23.10 (default installer/subiquity). It...
My comment above was in response to your initial post which contained very limited information and you had to be asked before you posted information...
The way out is to use a different packaging type. Prefer the .deb packages if they are available. 2nd choice is Flatpak. I know the Flatpak versions...