Today, we verified the OLTF of the RFC, which was 200 Hz and 0.5 rad of phase margin (See Fig. 1). However, this loop should have a unit gain at 180 Hz ideally. So we changed the RFC gain on the DSP card from -0.25 to -0.22. The new OLTF is shown in Fig. 2:  the unit gain is now at 178 Hz and the phase margin is now at 0.62 rad. The gain margin is now 0.5 and it was 0.6 before.

Ps. to be noted that if the DPS card is reloaded the RFC gain will be reverted to -0.25 again.