Measurements and residuals of the monopole (left) and quadrupole (right) moments of the power spectrum for the true and reconstructed halo number density fields from the Fiducial QUIJOTE simulations. Results are computed on 64³ grids and averaged over the 20 test fields (mocks 500–519). The color scheme is consistent across all figures and described in the legend. Dashed curves correspond to training on mocks 0–79 with mocks 80–99 used for validation, while solid curves correspond to training on mocks 0–399 with mocks 400–499 used for validation.