How do I remove duplicate devices from Devices and Printers "Add a device" listing?

This list has been nothing but problematic. I have two shieldTV units. I have 1 which does not show up at all, and the other is showing up twice.

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I’ll work on finding out why the 2nd isnt showing up later. At current i’d like to find out how to clear this list so it doesnt see the same unit twice. Worth noting I did replace the unit thats appearing twice about 6 months ago via RMA. Assume that has something to do with it showing more than once.

Still i’ve reset the gateway and router, ive cleared the dns/arp/route tables/caches. I have no idea where this stuff is cache’d at thats resulting in the above, but would love a resolution.