LM25085: CC/CV Mode ripple when exceeding current limit

Hi, I am making a CC/CV board using LM25085 according to AN-2157 with the following spec:

1) Input Voltage: 22.8V ~ 25.2V

2) Voltage mode Output Voltage: 20V

3) Current mode Current Limit: 3A

The basic circuit follows the following Webench attached below.

Board operates well with current below the limit. However if the load current exceeds some limit (around the current limit set), the output voltage give some oscillatory behavior.

I tested with electronic load by adjusting load resistance. Following 3 figure give the behavior

1) v_below limit => the voltage output gives normal behavior

2) v_just above current limit => load resistance lowered to increase the load current just above the limit => voltage output starts to oscillate.

3) v_load impednace further lowered => load resistance lowered further => voltage output oscillation increases (even the average voltage lowered, and the average current remains below the limit)

Please give me some advice or comment to resolve this problem (regulate the voltage).

(CC/CV circuit used the same component values given in  the application note except amplifier multiplier)