So yours is the “made for” insert, the real Nova insert D is right hand, and the dual threaded real Nova is T. Yours should look like the picture in the above link which is also a dual threaded.
I don’t know if being dual threaded can make the chuck back off of the insert or not.
I would think not but maybe someone else knows.
When I need it, which is rare, a large pair of channel locks fits between the chuck and headstock on my lathe.
If you ordered the wrench from Nova did you ask about your problem with the insert unscrewing?
Link to Nova service center
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