Need help with tweening y rotation by 90°

Hi, this is somewhat embarressing because i cant even do this:

On Button click rotate an instance in a camera rig by 90 degrees.

I usually set up a camera rig such as:

containerentity: Used for positioning/centering

  • yrotationEntity: rotated around y (left/right)
    – x rotation entity: rotate around x (angle up/down)
    — camera: (use position z to zoom)

But i can´t come up with a tween solution around Y by 90 degrees. Some success is with the first rotation, after that it jumps back. I guess i run in gimbal lock, although i tried converting eulers to Quat.

RotationManager.prototype.onRelease = function (event) {   
    if ( this.isTweened == true) {
        return;
    }
    this.isTweened = true;
    var rot =  this.YrotRigNode.getLocalRotation();
    var targetEulers = this.YrotRigNode.getLocalEulerAngles().clone();
    targetEulers.y += 90;
      
console.log("y rotation center = " + this.YrotRigNode.name);
    
    this.rotQuaternion.setFromEulerAngles(targetEulers.x, targetEulers.y, targetEulers.z);
        var tweenRot = this.app.tween(rot).to(this.rotQuaternion, 5, pc.SineInOut);
       
        tweenRot.on('update', function (dt) {
             this.YrotRigNode.setLocalRotation(rot);
        }.bind(this));
        
        tweenRot.on('complete', function () {
            console.log('rot tween complete');
            this.isTweened = false;
        }.bind(this));
         tweenRot.start();
         
};