Exported C++ introducing unwanted harmonics/distortion in plugin

Hey all,

I'm working on a simple audio FX with the idea of first developing it as a Max4Live device, using RNBO, and then exporting the C++ to be used in my custom JUCE project (so I can add a custom Ui etc.)

The FX is basically doing a simple (bell) filter sweep across the frequency spectrum.

It all seemed well until I tested with a simple sine wave as an input and realised the VST plugin is actually introducing distortion.

The Max4Live device, however, doesn't do that and sounds completely fine.

Since, according my understanding at least, the Max4Live device and the VST share the same exact C++ code at this stage, I thought the issue could be in the way I used the RnboObject inside my C++ project, so, as a test, I tried exporting the VST directly from RNBO (the one with the auto-generated GUI) and surprise... That's also introducing distortion!!

So I wonder, given that the issue isn't due to the way I interfaced the exported C++ code with my code, could that be a RNBO bug?

Thank you!