Cannot map FX Freq to controller

Elektron Gear Syntakt
1

Hey, need help with mapping FX Freq to midi controller, new to synth to I might have done something wrong.

Tried both channel 13 and 14 (setup shows 13 is the FX channel), any CC not just 70 doesn’t work for FX
Any other mapping does work (ie. can map mod wheel for each channel or direcr mapping).

What could I miss?

2

Self-answer.
Syntakt FX channel can be controlled by midi controller when it is connected via MIDI. If both connected via USB to a laptop FX channel does not bind but instrument channels do.