Does the file naturally disappear with Winscp?

■ Does the file naturally disappear with Winscp?
In Winscp, connect local (PC) and host (Linux server).
With several hours left on the connection, the file (server certificate) that was on the host side of Winscp has disappeared.
Have you ever had nature and files disappear in winscp in the past?
(I examined, but no such information)

※ There is no connection with the external network, there is no access from the outside.
Also, since there is nobody, it is not erased by human operation.
Appach (httpd) is working, but the server certificate is read only.
※ I also asked RedHat Linux. Both OS and Apppace received answers that there are no daemons etc. that automatically delete files

•Version of WinSCP you are using (Ver5.6.3).
•Version of Microsoft Windows you are running WinSCP on : Windows 7
•Transfer protocol (FTP).

■ Does the file naturally disappear with Winscp? (PART - Ⅱ)

In Winscp, connect local (PC) and host (Linux server).
On the host side of the Winscp screen, double-click on the file → the contents were confirmed in the editor (implemented for multiple files).
After that, we left for several hours.
Then, all the files seen on the host side had disappeared. There was a file not seen on the host side.
I do not know why only the file that confirmed the contents on the host side disappeared
Have you ever had nature and files disappear in winscp in the past?
(I examined, but no such information)

It's very unlikely this has anything to do with WinSCP. I assume the files disappear even if WinSCP was closed.