[Bug]: Nextcloud will not start minimized (despite --background)

### ⚠️ 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

Nextcloud doesn't minimize for the past months (year?) for me. Despite using the `--background` flag.

### Steps to reproduce

1. Use Linux Mint XFCE or any XFCE desktop I assume
2. Execute Nextcloud with `--background` flag: `/usr/bin/nextcloud --background`
3. Nextcloud desktop will start, however **NOT** minimized. Despite the `--background` flag.

### Expected behavior

Nextcloud desktop should minimize when using `--background`!

### Which files are affected by this bug

NA

### Operating system

Linux

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

Linux Mint 22 XFCE

### Package

Official PPA: https://launchpad.net/~nextcloud-devs/+archive/ubuntu/client

### Nextcloud Server version

30.0.4

### Nextcloud Desktop Client version

3.15.2

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

Fresh desktop client install

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

Encryption is Disabled

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

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

### Nextcloud Server logs

```shell
Not applicable
```

### Additional info

See video:

https://github.com/user-attachments/assets/fa91be55-5df2-48be-87ae-e38b9c064c63

[nextcloud_debug_archive.zip](https://github.com/user-attachments/files/18240079/nextcloud_debug_archive.zip)

Ps. also you desktop client will keep logging the `Nextcloud_sync.log` in the old `~/.local/share/Nextcloud` location. Instead of the new `~/.config/Nextcloud`.