Damping optimum - something ain't right

I have to determine the gain K and the integrator time T_i of my PI controller to control my motor speed. I have to chose K and T_i according to the damping optimum which has 5% overshoot and short settling time. No matter how much I rewrite and calculate I can't get my result to overshoot like it should for the damped optimum response. Down below are some pictures. Appreciate the help and insight.

https://preview.redd.it/f582y5niidee1.png?width=1192&format=png&auto=webp&s=1882816705f28bd93557c28deefc910aed688fbe

https://preview.redd.it/nqlj664addee1.png?width=1628&format=png&auto=webp&s=f1bce453c2c1642509b750d4d14da99eb032c715

https://preview.redd.it/0rh7764addee1.png?width=1628&format=png&auto=webp&s=da4d1e46a5eeccc85bb5b55c754041ceb94e65d3

https://preview.redd.it/ikh2q44addee1.png?width=1000&format=png&auto=webp&s=e5af241f65a74a834e091e50cfccaa0a4814bd1b