SOC estimation Extended Kalman filter

based on the explanation from this video (https://de.mathworks.com/videos/modeling-and-simulation-of-battery-systems-with-simulink-1638227640905.html). I have created a very accurate Equivalent circuit model of a lithium battery. the problem I have is estimating SOC using the Estended Kalman filter method. the true Soc and the estimated Soc with the Ekf are not similar. I certainly have some errors in the parameterization of the extended kalman filter. can anyone help me to resolve this. I habe set the real SOC initial Value to 1 . When i set the Initial SOC of the EKF to 0,7 the curves of the two soc should normally get closer after a while. since lExtended Kalman make predicts, measures and improves predictions.