Hallelujah! I have solved the problem, and it was simpler than I think...
The problem was the recycle, or better, the problem was my knowledge about networks and nas(ses???).
Anyway, when I emptied the recycle I logged with my account and I saw all images of my pc made with Acronis (maybe, seeing that only my pc images was in the recycle should be an alert............................. shame on me!).
So I logged using Linux with every user and I found many Acronis images! So now everything has back to normal!!!
I have a question.
When I enter the NAS using a browser, in the file explorer I see:
Volume_1
|- Work folder
|- Backup
|- Private folder
Using Linux if I enter the NAS folder what I see is:
Backup
Work Folder
Recycle Bin - Volume_1
Private Folder
Volume_1
https://postimg.cc/gallery/3byttn1se/In that recycle bin there were all files I deleted. How can be possible that the only way to see that recycle bin is using Linux?
When I created the Network Shares (Work, Private, Backup), I thought that every share has his own recycle, why everything goes in a general recycle that I can't see in any way? I can't everytime boot from a live linux to check if everything is normal...
@Ivan: thank you very much for you help, patience and time!