Windows 11 Explorer and other Apps (Word, Firefox ...) freez with NextCloud Client 33.0.x and 34.0.x (up to 34.0.2 (updated))

### ⚠️ 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

Just a quick note: There are one or two posts here describing similar issues.
https://github.com/nextcloud/desktop/issues/10123 (in this case, the client also loses its connection to the server during synchronization, whereas in my case, the Apps simply freezes without NextCloudClient losing the connection to the server)
However, since the symptoms differ slightly, we were advised on the NextCloud forum to create separate bug reports and let the developers decide whether they are related to the same issue.

Bug description
On Windows 11, when using VFS with very large NextCloud user directories, the NextCloud Client 33.0.x and 34.0.x causes Explorer or other programs that are currently performing write operations on the file system to freeze (in my case, for 30–40 seconds).

I tested all client versions from 33.0.2 to 34.0.1 (updated) for several days each. The freezes disappeared immediately every time after downgrading to client 4.0.8 again.

Not every save operation is affected. For example, if I save 10 files one after another from Firefox to the NextCloud directory structure, the first 2 or 3 work without any problems, the fourth freezes, and then a few more work until the next freeze.

### Steps to reproduce

1. Need a big nextcloud folder (My NexCloud Folder Explorer Information Size: 860 GB; Size on disk: 425 GB; Contents: 360,000 files, 12,000 folders)
2. Interact with the filesystem in the nexcloud folder (move single files, save files) 10 to 20 times in a row with individual files

### Expected behavior

Regardless of whether the NexCloud client has started a SyncRun, the programs should continue to run without freezing

### Which files are affected by this bug

All files

### Operating system

Windows

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

Windows 11

### Installation method

Official Windows MSI

### Nextcloud Server version

33.0.6 (updated)

### Nextcloud Desktop Client version

34.0.1 (updated)

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

Major version update (i.e. 4.0.0 → 33.0.0 or 34.0.0)

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

No

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

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

### Nextcloud Server logs

```shell
No relevant server log entries.
```

### Additional info

Unfortunately, there are no clear entries in the logs (client and server) that indicate the error. However, since the error disappears immediately every time I downgrade to Client 4.0.8, I take this as an indication that the problem lies in the changes made between Client 4.0.8 and 33.0.x.

It is also notable that the freezes end at the exact same moment (to the nearest second, as far as can be determined by the Windows system clock) when the log shows “SyncEngine finished without problem. ... "Success"” and log rotation occurs.