TDR NOVA - Difference between Mono and Stereo

[heavymetalmixer]

I've been using TDR NOVA for a while as my go-to EQ, but today I noticed something weird.
When I use it on Mono tracks (Kick, Snare, Toms in the center) and flip betwen Stereo and Mono modes inside Nova the sound changes.
Is this a bug or an expected behavior and why?

[AdamCadabra]

Not sure if this helps, I tried to replicate the same problem using stereo and mono samples back to back on the same track then alternating Nova's output from mono to stereo and couldn't get a result that sounded different. I did notice I was using version 1.2 and needed to update. Repeated the same process after the update with the same results. Maybe a bug? If you give me more details I can try and better replicate the same setup and tell you what happens on my end.

[heavymetalmixer]

Besides what I said the only info I could provide is this:
1) Reaper 6.18 x64.
2) Windows 10 Pro.
3) Audient iD14 interface.

Also, I noticed something weird when doing a null test in SPAN after I noticed this sound difference:

As you may already know a null test is all about checking if both tracks null each other completely when one is phase-flipped, and this happened when I did test to the drums I mentioned when both tracks were Stereo or Mono. But if one was Stereo and the other Mono, SPAN registers a very low level signal on the RMS and True Peak numbers, even though the analyzer shows nothing.

[FabienTDR]

Can you try to capture the problem with a small sample and upload it here with the plugin state? I can't produce any issue with the mono mode, but maybe you had an exotic configuration that I didn't try.