Deletes files from the repository spontaneously :(

Please forgive me if I put this question into an inappropriate section. I can’t speak English much.
I have a problem with my nextcloud :frowning:

I do not know how to explain it on a folder containing a large amount of images (about 5500 images / 6gb) in different directories and subdirectories. These images are not lost to me from the local storage and I will find these files in the deleted ones. I’m 100% sure I didn’t delete this data.

I will try to restore the files (on the server via the web interface), the file recovery will start and for a while it seems that the problem is resolved, but as soon as it is restored, that is, on the local disk, the data is available again the local computer will disappear again!

Files are not physically on the local disk!
However, Nextcloud sees the files in the application and takes them as restored.
On the server, the data is physically located in the restored folders.

It seems to me that the local change file is being corrupted, where I am writing the changes.

Da is something to do? Is there any way to restore / repair these parts? Is it even possible ?

Or do you know what this could cause?

With this folder it happened to me several times and only helped to completely change the location of the root directory and new synchronization. Since this is a large amount of data (total 0.3Tb), this unexpected recovery is quite limiting :frowning:

Application Version: 2.5.1 (now updated to 2.5.2)
Windows 10 64bit.

Thank you in advance for your reply.
I attach pictures to the situation