file a dupe of file at destination

I have created a move step with the option "if file exists - throw the file away".
Whenever a file has existed at the destination, but was deleted, the rule still discard the move.
The log says: File Event] File moved: File .../IMG_3355.JPG is a dupe of file at destination. Moving to Trash.

Why is that?

The file is a duplicate, which means that it is an exact copy of the file at the destination. If you have the "Throw away if duplicate" option checked, then it will do just that and throw it away.

The issue is that there Is no file with the same name at the destination. There was but I deleted it before I ran the rule again

It doesn't have to have the exact same name. It has to have a similar name, like the same name but with a number appended to the end.