I finally found the real reason for this: 4 hinge rotators for korolev cross are attached on the core stage after the booster separation, after I attached the rotators to the boosters instead of the core stage, the issue solved. But this is still a bug anyway...
I finally found the real reason for this: 4 hinge rotators for korolev cross are attached on the core stage after the booster separation, after I attached the rotators to the boosters instead of the core stage, the issue solved. But this is still a bug anyway...