Phones Channel Vst AmbiDecoder - Sidechain activation for head-locked signal is not preserve

For every ambisonic project in Nuendo 12.0.40 using head-locked signal, the sidechain activation of the phones channel in Vs tAmbiDecoder is not kept or saved. It needs to be reset every time I open a project or Nuendo as well as it routing. This is working in Nuendo 11.