The problem I see with your approach is that you are trying to simulate all input frequencies at once and are going beyond the Nyquist frequency of the circuit at the same time. A sine at the input of these circuits will not just cause a frequency component at the input frequency in the output signal, but also at other frequencies (where you also might have an input signal). Have you already looked at the output spectrum when you just have a single frequency at the input? But the main reason why you are not seeing a repetition in the result for circuit B) is probably that you are sampling the piecewise constant output signal, which causes a multiplication by the sinc function and gives you the cyan curve as a result.
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