How to not delete the original file when dragging and copying

How to not delete the original file when dragging and copying

That should not happen (by default). Where exactly are you dragging the file from and to? What version of WinSCP do you have installed?

What is you settings on this preferences page?
https://winscp.net/eng/docs/ui_pref_dragdrop
What is the "shell extension" status displayed there?

This is my settings

version 5.21.2

Thanks. Though, you didn't answer this question:

Where exactly are you dragging the file from and to?

Drag remote files to the desktop

I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.