Polarization of vector bosons offers unique avenues for exploring the Standard Model (SM) of particle physics and effects going beyond. Two such approaches investigate delicate gauge cancellations at high energies in W^±Z events where both bosons are transversally polarized (TT) and the energy dependence of the fraction of events where both bosons are longitudinally polarized (00). The former is known as the radiation amplitude zero (RAZ) effect. To achieve this, events with leptonically decaying W^±Z bosons are selected in the Run 2 data of the ATLAS experiment at the LHC. This data was recorded at a center-of-mass energy of √s = 13 TeV and encompasses an integrated luminosity of 140 fb⁻¹ . The fraction of doubly longitudinally polarized events in a region with p_T^WZ < 70 GeV and 100 < p_T^Z ≤ 200 GeV is measured to be 18.9 ± 3.4 3.3 ( stat. ) ± 2.4 2.2 ( syst. ) %. When the p_T^Z cut is changed to p_T^Z > 200 GeV, the value is determined to be 13 ± 9 8 ( stat. ) ± 2 2 ( syst. ) % . The former is accompanied by a significance of 5.2 σ over the null hypothesis that no 00 state exists. If the measurement is performed with a more restricted model, evidence for the 00 state is also found in the p_T^Z > 200 GeV region with a significance of 3.2 σ . Using 100 < p_T^Z ≤ 200 GeV, a lower bound of 2.8 σ is determined for the significance of rejecting the hypothesis that the fractions of longitudinally polarized W^± and Z bosons are independent of each other. The RAZ effect is probed through the unfolding of the ΔY (WZ) and ΔY (ℓWZ) observables for the TT polarization state and the sum of polarizations in regions requiring p_T^WZ to be smaller than 10 , 20 , 40 , or 70 GeV, or unconstrained. Here, the effect is realized as a reduction of the differential cross-section around ΔY = 0 . A depth variable (D) is introduced to quantify the size of this dip and measured to be 0.68 ± 0.10 and 0.29 ± 0.06 for the TT state in the region with p_T^WZ< 70 GeV using ΔY (WZ) and ΔY (ℓWZ), respectively. The former represents an estimated significance of D / ΔD = 7.0 and indicates a precise measurement of the depth.