Problem simulating model in simulink - Strange results in high frequency

Dear Matlab community,

I constructed two models to simulate the same dynamical system. One was done coding and was solved with ode45 in the workspace. The other version was done in simulink. The two versions perform as expected (graph results are equal) up to a certain frequency. As frequency gets higher than 29rad/s, simulink model starts to give some non-sense results, with one of the states oscilating indefinitely around its equilibrium point, whereas in the workspace, this same state under the same conditions, goes back to its equilibrium point, as expected. I verified the model configuration parameters, which happen to be exactly the same. I also tried to reduce the max step size to a very low number (0.0000001) but the same strange result is still appearing. Could someone please help me with that?

Regards,

Allan