Track Panner can`t be disabled / send out Mono


I am working with the Sennheiser VR Mic and recorded direct from the 4 Mono Inputs.
After exproting to an 4 Channel MultiTrack .wav, i reimported to an Ambisonics FOA Track.
On the Track i used the AMBEO A-B Format Converter. Until Here everything works fine.

To listen to it, i setup the Output FOA Bus as Main and can listen thru the Cubase binauralizer on headphones.

If i now want to use 3th Party Plugins which convert it to Binaural, and insert them on the FOA Track, the Audio is not processed well.
(it makes no difference if I use the Stereo Out or FOA as Output)
The Problem is, that the Panner, (in this case the Multipanner at the Tracks Output, cant be disabled.
Even if I klick on the disable Button within the Panners GUI it still works.
In some cases it switches, but make then a Mono Output.

I guess this is a Bug?!