[Bug]: Connection to Nextcloud could not be established

### ⚠️ 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

I'm using VFS on macOS. When I copy a folder, then the copy process waits for a moment an then fails with the error 'Connection to Nextcloud could not be established'.

The client log shows the following entries (exported via Debug archive):
```
2025-11-07 21:31:41:869 [ warning nextcloud.sync.pushnotifications /Volumes/builds/34594/macos-34594/src/libsync/pushnotifications.cpp:127 ]: Websocket error on with account QUrl("https://nextcloud.example.com") QAbstractSocket::RemoteHostClosedError
2025-11-07 21:31:41:869 [ info nextcloud.sync.pushnotifications /Volumes/builds/34594/macos-34594/src/libsync/pushnotifications.cpp:59 ]: Close websocket for account QUrl("https://nextcloud.example.com")
2025-11-07 21:31:41:869 [ info nextcloud.sync.account /Volumes/builds/34594/macos-34594/src/libsync/account.cpp:357 ]: Disable push notifications object because authentication failed or connection lost
2025-11-07 21:31:41:871 [ info nextcloud.sync.pushnotifications /Volumes/builds/34594/macos-34594/src/libsync/pushnotifications.cpp:98 ]: Disconnected from websocket for account QUrl("https://nextcloud.example.com")
2025-11-07 21:31:42:258 [ info nextcloud.sync.credentials.webflow /Volumes/builds/34594/macos-34594/src/gui/creds/webflowcredentials.cpp:411 ]: request finished QUrl("https://nextcloud.example.com/ocs/v1.php/cloud/user?format=json") with request id "de883b08-d6d2-4fad-b6ea-3bfe6b95e935"
```

On Linux and Windows Desktop Clients everything works perfectly.

I could not find any related issue on Github issues.

### Steps to reproduce

No idea how to reproduce this.

### Expected behavior

Copying of folder from Nextcloud is working.

### Which files are affected by this bug

Copying any folder from Nextcloud is affected.

### Operating system

macOS

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

26

### Package

Official macOS Virtual files 12+ universal pkg

### Nextcloud Server version

32.0.1

### Nextcloud Desktop Client version

4.0.1

### 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?

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

### Nextcloud Server logs

```shell

```

### Additional info

_No response_