The AGC of this rig on SSB seems to be too fast, but on AM it is considerably slower. SSB uses medium speed, while AM uses medium and slow speed together. This problem is easily cured by connecting slow and medium time delays in parallel, when AM time delay is used on SSB. CW and RTTY remain still original fast delay.
Open bottom cover and find R1807 and R1808 on top side of main board near J2602 (DSP AF connector). Connect their ends (connected toward to sw transistors), together with small jumper (arrow) and that's it.