The problem of strange frequency response after switching the modes, 7.1, 2-CH and HiRes, is still present in beta firmware v2, (named 20180111), the one that incorporates the "3-D On"-mode.
The frequency response goes to normal after switching EQ-presets once.
When testing today another strange thing of that sort appeared, when powering up Mobius there was a 3dB boost around 300Hz that only went away after a Mobius power cycle, after Mobius crashed the iPadPro and itself, with the Gypsy Muse becoming speechless.
Mobius was connected through the first version Apple USB CCK, with Mobius charging switched off before plugging it in.
It seems the internal DSP can easily become confused.