Distribution of predicted semi-amplitude classes for systems without injected planetary signal (the “no planet” scenario). Amplitudes are expressed in m s⁻¹. The predictions are heavily skewed toward the lowest amplitude bin, with over 80% of samples assigned to this class. While the remaining predictions are primarily assigned to the correct no planet class, the overall classification accuracy remains limited to approximately 20%. This reflects the model’s tendency to infer low-amplitude planetary signals even when none are present. This highlights the model’s tendency to predict low amplitudes in the absence of a true planetary signal.