[Bug]: nextcloud-client shows empty transparent GUI on gnome-xorg

### ⚠️ 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 GUI doesn't show up on gnome-xorg. (but it works perfectly on gnome-wayland).
After initial configuration, if you start nextcloud client again, the GUI doesn't appear. Windows manager shows a transparent window (Screenshot attached)

This issue could be easily reproduced in fresh-installed Arch Linux, on both laptop, desktop, and QEMU virtual machine. I tested different AppImage, showing:

|NextCloud client version|Result|
|---|---|
|3.15.0 from Distro-Repo|Bad|
|3.15.2 AppImage|Bad|
|3.12.8 AppImage|Bad|
|3.12.1 AppImage|Bad|
|3.11.2 AppImage|Bad|
|3.3.0-rc1 AppImage|Bad|
|3.2.4 AppImage|Good|


> Note1: Nextcloud client doesn't print any abnormal error message. Sometimes, I just keeps trying, it sometimes (rarely) randomly fixed itself. I don't know the reason.

> Note2: I always kill the background nextcloud daemon before doing my test. Doesn't make any difference.

### Steps to reproduce

1. Deploy fresh minimal Arch Linux installation.
2. Install the following packages.

```
pacman -Sy --noconfirm fish dhcpcd vim sudo openssh
useradd --create-home --shell /usr/bin/fish recolic
echo 'recolic ALL=(ALL) NOPASSWD: ALL' | sudo EDITOR='tee -a' visudo

pacman -Sy --noconfirm gnome networkmanager power-profiles-daemon nextcloud-client firefox xorg-server
systemctl enable gdm NetworkManager power-profiles-daemon
```

3. Reboot. When login, choose `gnome (wayland)`. In gnome, start nextcloud client. This is good case, everything works in wayland.
4. Reboot. When login, choose `gnome on xorg`. In gnome, start nextcloud client. This is bad case, GUI doesn't show up. You got a repro.

Additionally, you can try downloading different version of AppImage. It repros on 3.15.2, 3.12.8, 3.12.1, 3.11.2, and all older version.

### Expected behavior

Nextcloud client GUI should show up.

### Which files are affected by this bug

/usr/bin/nextcloud

### Operating system

Linux

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

Arch Linux rolling

### Package

Official Linux AppImage

### Nextcloud Server version

N/A (this issue is not related to server side)

### Nextcloud Desktop Client version

Tested 3.11.2, 3.12.1, 3.12.8, 3.15.0, 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?

N/A (this issue is not related to server side)

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

N/A (this issue is not related to server side)

### Nextcloud Server logs

N/A (this issue is not related to server side)

### Additional info

I tried to set environment variables such as

```
QMLSCENE_DEVICE=softwarecontext
QT_OPENGL=software
LIBGL_ALWAYS_SOFTWARE=1
```

no effect. Other QT application (such as qBitTorrent) works fine on the same machine.

This bug doesn't affect nextcloud-client functionality. It still sync files in background if I did configuration in wayland session.