⚠️ Before submitting, please verify the following: ⚠️

• This is a bug, not a question or a configuration issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server and Desktop Client are up to date. See Server Maintenance and Release Schedule and Desktop Releases for supported versions.
• I agree to follow Nextcloud's Code of Conduct

Bug description

After having uploaded a few thousand JPG images from another computer (Windows 10) without issue, when these changes have been synchronized to my Linux laptop (Kubuntu 22.04) with virtual files enabled, all the files in some specific subdirectories disappearing after the client (v 3.5.1), while showing the message "Conflict when uploading a file. It's going to get removed!" for each one of them. See attached screenshot:

As I mentioned, only files in a few subdirectories have disappeared, but no from others. I can't find a reasonable pattern.

These files have only been deleted from the local machine, but remain in the server and in the Windows PC, so I believe it's an issue linked with the desktop client in the linux machine.

One more thing, these files are stored in an external storage and accessed via SMB.

Steps to reproduce

1. Upload a directory tree with files in one computer. Wait until synchronization finishes successfully.
2. Turn on second computer with linux and desktop client 3.5.1. Wait until synchronization finishes too.
3. Observe how some directories trigger this problem and many files disappear.

Expected behavior

All files from the server should appear in the client directory tree.

Which files are affected by this bug

No clear pattern. All affected files were .JPG

Operating system

Linux

Which version of the operating system you are running.

Kubuntu 22.04

Package

Distro package manager

Nextcloud Server version

23.0.2

Nextcloud Desktop Client version

3.5.1

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

Updated from a minor version (ex. 3.4.2 to 3.4.4)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

No relevant logs in the server. The issue seems to be exclusively from the side of the client.

Additional info

(I can provide the Debug Archive log if necessary, but the file is more than 500MB in size and contains lots of sensitive information)