This shouldn’t really happen. I don’t know of any tool that would do that.
However, try using file manager app and see if there is a file with another
namwe in destination folder (I don’t exactly remember now whether it’s same name
and different extension or completely different name). If there is try copying
it to another location and change the extension.

If that fails, you can check previews in the folder:

Is this problem reproducable, does it happen every time?