6RA80 Sinamics Control Module: Current Feedback Problem

There is single motor, with 12 pulse configuration (Master 6RA80 CM + Slave 6RA80 CM).
During Hot Strip Mill Running, the current feedback observed is as attached at both Load and No-Load Condition. This is leading to excessive current hunting both in EMF control mode and in Encoder feedback mode.

Following are the points those I had already checked:

1.External ACCT feedback continuity and polarity to CM. It is Okay.
2.The current lobes at ACCT secondary for two phases. It is Okay.
3.All gate pulses are checked in simulation mode. It is Okay.
4.Voltage six lobes in 20ms had been checked both in motor running and with Lamp-Load connected. It is okay.
5.Current feedback is available at connecter r52117 but in intermittent / discontinuous way as shown in the attached recording.

But, I am not getting the 6 Current Lobes in 20ms from the controller by connecting connector r52952 at Trace plot. Instead I am getting some flat-topped stepped waveform, which is not intended as enclosed.

I had even replaced the A2 Power Supply Cards two times along with CUD. But there is no effect.

The firmware version is now V1.3, Hotfix 5.

What can be the other necessary things that should be checked in order to get correct waveform? Is there any doubt from the controller point of view mainly related to the firmware. The controller is presumably not able to read and control the current feedback. How this can be overcome?

There was my doubt on the encoder feedback also as the current control set-point is also oscillating. But there is no good effect when I changed it to EMF mode of control.

The Mill is at Shut Down. Please help and suggest.