Copter vibrates in Loiter because of gimbal DJI RS 2 pro in alt hold everything is ok

Hi
I installed DJI RS2 Pro gimbal on octocopter on coaxial frame. Copter was flying ok parameters were get from succesfull autotune. Gimbal was working ok. But I wasn’t satisfied with the isolation of gimbal from the copter. I had same bed vibrations in the video. So I changed the vibration mounting for gimbal. This antivibration mounting I tested in my earlier builds with success they are working in my 3 other copters with different gimbals. But in this copter DJI RS2 pro in “Loiter mode” starting to make small moves in roll and whole copter vibrates. Everything is ok in “Alt hold” and “Pos hold” but when I switch to “Loiter” gimbal starting to vibrate in roll. It’s like pendulum effect. I tested many DJI RS2 pro settings with lower strength of stabilisation, with different firmware etc. I can’t find settings for gimbal which will help with this moves in roll during loiter. It looks like vibrations from the copter in the loiter mode provokes the gimbal to movement in roll… What can I do to resolve this problem. Lower the PIDs of the copter ? Maybe other setting ??? I checked 3 different antivibartion mountings for gimbal with 2 I have this bed moves with 1 it is ok but vibrations on camera are too high.
Any idea what can help me ?