Howdy! I don't actually have a Victor so I'm not 100% sure, but in the manual it says this about the gate input:
"GATE IN – use this 3.5 mm TS jack socket to activate
the onboard mix envelope from an external
source. The GATE input expects a v-trig rising from
0 V to +5 V."
Whereas the Plaits has an actual built in LPG/envelope for amplitude, it looks like the purpose of the gate on Victor is to trigger an envelope that sweeps the onboard oscilator mix. Does that sound right? I also noticed the USB/Midi jack says specifically it does not respond to note on/off which makes me think it doesn't have internal VCA capabilities. I think you'll want to run it into an external VCA and use gate from the GM to trigger an envelope to control it. Cheers!