macOS: Changes are not synced anymore after some time

### ⚠️ 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 have searched for 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've lost track of the numerous sync issues with the macOS File Provider client, but I'd like to try to provide useful feedback to help resolve the issues as soon as possible.

It seems that after some time, the File Provider client gets out of sync and does not see some changes on the server, despite using notify_push.

### Steps to reproduce

1. Use macOS File Provider extension
2. Create a new folder in Nextcloud (on root level) using macOS
3. Use the web app to navigate to the new folder
4. Create a new text document inside the new folder using the web app

The new file is not visible on macOS.

### Expected behavior

I expect the file to be visible on macOS after some time.

### Which files are affected by this bug

any

### Operating system

macOS

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

macOS 26.6.2

### Installation method

Other

### Nextcloud Server version

34.0.3

### Nextcloud Desktop Client version

34.0.2

### Did this occur after an update or on a clean installation?

Minor version update (i.e. 33.0.0 → 33.0.1)

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

No

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

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

### Nextcloud Server logs

```shell

```

### Additional info

Additionally, as `Library/Containers/com.nextcloud.desktopclient.FileProviderExt/Data/Documents/Logs/log.txt` shows, the root level is being requested upon the change (`Network response request: https://cloud.example.com/remote.php/dav/files/username, result: success(22355 bytes)`), but the new folder isn't. It just does not seem to be known to the File Provider extension.

Now there is another problem:

- In this state, create a file with the same name in the folder on macOS.
- The file is being synced, and the file on the server is being **overwritten silently**.

But still, if I delete that file on the server, the deletion is not propagated to macOS.

- Now, with the file deleted on the server and still present on the client, delete the file on macOS
- The status in the menubar changes to the warning "X", and the menu says **there are conflicts** (but does not show which files are conflicted). Neither the "Resolve" button, nor the "Sync now" button in the Activities window do anything.
- Restarting the client seems to help sometimes but not always.

Resetting the file provider domain does help for some time. But eventually the state described above state will return again.

Start by reproducing the macOS File Provider sequence described in the issue and inspect Library/Containers/com.nextcloud.desktopclient.FileProviderExt/Data/Documents/Logs/log.txt, especially the root-level DAV request. Trace why the new folder and later server changes are not propagated, then verify that syncing, deletion, conflict reporting, and Sync now work without resetting the file provider domain.

Written by the indexing model from the issue text.