I was able to build it.
❯ nixos-rebuild build --flake .#vm-intel
building the system configuration...
warning: updating lock file '/home/will/code/external/nixos-config/flake.lock':
• Updated input 'nixpkgs':
'github:NixOS/nixpkgs/c68a9fc85c2cb3a313be6ff40511635544dde8da' (2024-02-15)
→ 'github:nixos/nixpkgs/b7ee09cf5614b02d289cd86fcfa6f24d4e078c2a' (2024-02-26)
warning: Git tree '/home/will/code/external/nixos-config' is dirty
For some reason it updated the lock file.
nix store verify
I think is a red herring. I get the same issue on my flake system config.
Do you only get that error when switching?
Perhaps related to: Getting "secret key is corrupt" on most commands · Issue #45339 · NixOS/nixpkgs · GitHub
Perhaps try deleting your lock file and rebuilding.