The RFC didn't relock after this operation. I had to change de demodulation phase from -2.229 to 1.529 rad.

ACL_CONST_CH    RFC_6MHz_phi0     "rad" 0      LOOP_FREQ 1.529 #-2.229

I have not fine tuned the demodulation phase but it was enough to relock the RFC and lock the 3km arms.