Help needed with D.I Plus effect (MXR D.I.+ simulation)

Hello all,

Sorry if I'm spamming in the wrong place.

Using ToneLib, I'm trying to create a modern metal sound on my B3n by combining a clean, compressed low end with a distorted high end. For this I want to use the MXR D.I.+ (in combination with other effects), which should allow for blending a EQ'd clean (Cl) channel with a distorted (Ds) channel. However, it looks like the Ds channel is not working. For instance, when I turn the Cl volume to zero I get no signal out, no matter what I set the Ds volume and blend knobs to. There is only output when Cl is not zero, but not distorted. The Ds volume and gain knobs don't seem to do anything. What's going on here?

Example settings, just using the D.I Plus effect, has no output signal:
Bass 50, Middle 50, Treble 50, Color On, Cl volume 0, Blend 50, Gain 50, Ds volume 100

I have two Zoom B3n pedals and both have the exact same behavior as described above.

Any help or explanation is much appreciated!