The nonlinear Hall effect (NLHE) provides a powerful probe into the quantum geometry and crystalline symmetry of time-reversal symmetric systems. However, the evolution of its underlying mechanisms across different transport regimes in semiconductors remains a subject of intense debate. In this work, we systematically investigate the NLHE in hydrothermally synthesized p-type 2D tellurium (Te) nanoflakes. By implementing oxygen plasma-assisted contact engineering, we achieve high-fidelity signal detection through the suppression of Schottky-barrier-induced artifacts. Our results reveal that the NLHE in Te is governed by extrinsic scattering, as evidenced by a precise quadratic scaling law at temperatures above 30 K. Notably, we identify a remarkable low-temperature scaling anomaly at TR ≈ 30 K, where the scaling slope undergoes a dramatic sign reversal, a phenomenon that coincides with the low-temperature transport crossover. Furthermore, thickness-dependent studies show a 3.2-fold enhancement in nonlinear conductance as the flake thickness is reduced to 16 nm, identifying surface-induced symmetry breaking as the primary trigger for activating the nonlinear transport forbidden in the ideal bulk lattice. These findings not only elucidate the scattering-driven origins of NLHE in 2D Te but also establish the effect as a sensitive probe for scattering mechanism competition and symmetry evolution in chiral semiconductors.