Well oscillator pitch is not supposed to change when applying 0V but, when connecting, the voltage source might ‘load’ the v/8 input of the module. That’s more or less what’s happening with Mangrove (it’s better explained somewhere in the mangrove thread), that’s why I started to tune my oscillators like that.
I don’t have this problem with DPO or Dixie, so I concluded that it’s just module-specific, some oscillators might need little workarounds to be tuned correctly. (I checked with the frequency meter on ornament an crime, when connecting René v/8 output (while at 0V) their pitch rise but just by a few (mili)cents, it’s not audible at all.)