Longitudinal hyperon polarization as a function of relative azimuthal angle in 20--60\% Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.36$ TeV for the second-order (left) and third-order (right) modulations. Statistical and systematic uncertainties are represented as bars and boxes, respectively. The distributions are fitted with second- and third-order sine functions for the left and right panels, respectively. The solid lines from the left panel represent model calculations of the longitudinal polarization for different viscosity implementations from Ref. .