[Bug]: E2E folders removed with sync client v4.0.4 working with v3.15.3

### ⚠️ Before submitting, please verify the following: ⚠️

- [x] This is a **bug**, not a question or a configuration issue.
- [x] This issue is **not** already reported on Github (I've searched it).
- [x] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

Client version 3.15 - folders remain correctly synced
Client version 4.0.4 - folders uncheck and remove from the local file system after every OS reboot or logout and back into the user account without reboot

This feels like a race condition in the client loading the nmemonic and detecting the presence of the encrypted folders.

Logs show all the encrypted folders being removed in

.config/Nextcloud/logs/20260120_1954_permanent_delete.log.0

e.g

```
2026-01-20 19:54:22:387 [ info nextcloud.log.permanent /usr/src/debug/nextcloud-client/nextcloud-client/src/libsync/propagatorjobs.cpp:106 ]: delete "Guides" ""
```

Guides being the encrypted folder inside Documents folder being the configured sync.

The other logs aren't showing anything of use.

My server needed upgrading from v29 to v32 which we performed whilst testing against the client version 4.0.4 for this issue.

Non-encrypted folders stay synced under the same folder sync without issue.

### Steps to reproduce

Sync an encrypted folder with the encryption key set in the 4.0.4 client
Reboot
Login
If you are quick enough to open the folder you'll see the files removing

### Expected behavior

Encrypted folders stay synced to the client
Checkboxes under the sync folder stay checked
Files are not deleted

### Which files are affected by this bug

Only files inside E2E encrypted folders

### Operating system

Linux

### Which version of the operating system you are running.

Arch Linux - fully updated

### Package

Distro package manager

### Nextcloud Server version

32,31,30,29

### Nextcloud Desktop Client version

4.0.4

### Is this bug present after an update or on a fresh install?

Updated to a major version (ex. 3.16.3 to 3.17.0)

### Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

### Are you using an external user-backend?

- [ ] Default internal user-backend
- [ ] LDAP/ Active Directory
- [ ] SSO - SAML
- [ ] Other

### Nextcloud Server logs

```shell
Currently running at level 3 logging, no errors shown in the server nextcloud.log file.
```

### Additional info

_No response_