3 DOF Robot's initial position and motion error using inverse kinematic block in Simulink.

I am attempting to control a 3-DOF manipulator by providing XYZ waypoints using a signal builder in conjunction with the inverse kinematics block. The robot model has been imported from SolidWorks.

The SolidWorks model appears as follows:

Where the X, Y, and Z coordinates for the end effector are -0.06 m, -0.26 m, and 0.32 m, respectively.

The Simulink model is attached below:

I have also attempted to run a simulation without the IK block by providing some inputs to joints q1, q2, and q3 to test the simulation model using slider blocks. By setting the joint values as q1 = -90, q2 = -90, and q3 = 0, I was able to achieve the same pose in MATLAB. The gravity is set as [0 -9.80665 0].

However, I'm unsure why I need to provide q1 = -90 to obtain the default pose for joint-1 (as in Solidworks) in MATLAB. Normally, the robotic arm should be in a vertical pose following gravity.

When simulating the model using the inverse kinematic block, the pose of the robot changes. The end effector moves to the negative z coordinate (as shown in the attached figure ) of the world frame rather than follwing the positive z-value. It appears to be deviating from the desired trajectory for the z coordinate (z = 0.32 at t = 0). However, the motion of the end effector in other coordinates is correct.

Mechanical Explorer view in MATLAB..

Unfortunately, I was unable to find a solution to make the simulation work correctly for this 3 DOF model. Thank you.

[Danaish]

Actually, I was doing a mistake in assigning the joint values for the initial guess as [0; 0 ;0]. It seems the robot.xml file doesn't follow the default home position for the robot (as in SolidWorks) in simulation and therefore its joint values can be set to get the default pose. I just randomly tried from pi/2 or pi values for the initial guess and that worked. However, I don't know why I need to set these random values for initial guess rather than zeros to get the simulation run starts from the set default pose.