No Improvement With Transparent Reference RCA Interconnects For Naim NDX 2 Streamer

I am in need of some guidance from those more audiophile educated than myself. I recently upgraded my 18-old system. My system now is: Mark Levinson 5805, Naim NDX 2 streamer with Naim XPS DR power source, Naim Uniti Core CD ripper to WAV files, and Transparent Super speaker cables.
I use the streamer mostly for music from Tidal and the Uniti Core. My dealer talked me into buying a pair Transparent Reference RCA Interconnects saying my system was good enough to benefit from the $3200 upgrade. After ~ 600 hours "burn-in" time, I have to say that the Refs don't sound any better than my 18-year old Transparent Supers. Transparent's VP even called me when I politely complained, explained how the Refs were tuned for the source impedance and suggested that my speakers may need to be re-positioned to which I replied that there is not much more room for adjustment.
I am wondering several things: if the Refs are simply overkill for Naim's mid-level streamer, or if Transparent "tuned" the boxes incorrectly, or if the Ultras would be better, or if a different brand of interconnects would be better, or fill in the blank.
Your thoughts would be greatly appreciated.