"Your key storage is out of sync" when MSK private key is missing

(reporting on behalf of a community member I'm supporting at a hackerspace)

### Steps to reproduce

1. open element desktop
2. there is the "Your key storage is out of sync" toast
3. click Enter recovery key and enter it from password manager

### Outcome

#### What did you expect?
recovery fixes itself

#### What happened instead?
"The recovery key you entered is not correct"

#### Devtools

The devtools say that the master private key is missing, while backup is connected correctly. Does is really make sense to try anyway? Should the toast perhaps go straight to "reset your identity"?

### Operating system

NixOS

### Application version

1.12.6

### How did you install the app?

nix pkgs

### Homeserver

synapse 1.145

### Will you send logs?

Yes