I am not sure how you can stop the movement. I thought you are using UDF but as I went through your previous post, it seems like no. However, you can increase the baffle rigidity by increasing Young's modulus. The idea is that if the flow field did not converge, it might apply extreme values of pressure on the structure. That is why I suggested running the flow field for some good time before it hits the baffle to ensure it reached steady state solution. n