asking help of tuning gain

[dzy666fly]

Hello, everyone. I want ur help about using gain tuner.
When I try to use gain tuner on the 6-DOF robot arm UR10 (and UR10e), I find that setting up joint limit seems to be important.
If every joint is limited to [-6.0, 6.0], the visual curve shows well.
However, if I set up the joint limit as the real world robot arm in our lab, it is weird that the second joint shoulder_lift_joint moves unexpected as follows. Well, other joints works well. How can I solve this problem?

The natural frequency is set to 25.0 and damping ratio to 1.0.
Every joint limit is set to [50,80], [-80,-40], [80,120], [240,300], [135,150], [120,150].
Thank u all so much!