MoveTo does not work as expected

I'm trying to move file abc.txt to a different folder and file name using the following code:

var files = client.ListDirectory("MyFiles/In").ToList();

foreach (var file in files.Where(f => f.IsRegularFile)) {
	var newFilePath = $"MyFiles/In/archive/{DateTime.Now:yyyyMMddHHmmss}-{file.Name}";
	file.MoveTo(newFilePath);
}

When the source file name abc.txt already exists in the archive sub folder the library throws an exception with message Already exists even though the target file name will have a different name (prefixed with a date time stamp).

Start at the file.MoveTo(newFilePath) call and reproduce the case where archive/abc.txt already exists while the destination uses a timestamp prefix. Trace how the move operation checks for an existing target; done when a distinct timestamp-prefixed destination is not rejected solely because the source basename exists there.