P-locking lfo depth on MIDI track

Im trying to set a trigless trig to activate the lfo on the end of the pattern but it does not work. Im p-locking the deapth. Ive also tried p-locking the destination. Am I doing something wrong or is it a bug? Workaround?

Im controlling a microkorg btw, if it matters. It works if im twisting the knob so I guess it shouldnt.