this issue is likely not the scope, but the simulation results. The easiest explanaion of why the results don't make sense is that too large a time step is being used to plot them well. The results can actually be correct, but look wrong because of the large time step. Please set the maximum step size to a small value and your scope data may clean up. If that doesn't work, then something is probably wrong with the model or solver settings such that the simulation is not converging.