You can also check the Refine Factor on the preferences of your simulink model. Default is 1, it's better to make it 4. Check this out if you would like
The factors asked are a method used and simulation parameters such as initial step size and tolerance.
At use the method (solver) and/or simulation parameters could not provide convergence of solution (i.e. stability) which cases may take place especially for stiff differential equations simulation accuracy is lost. It may be got at right option of simulation method and parameters.