This paper presents a new perturbative full-shape analysis of BOSS galaxy clustering data, combining the galaxy power spectrum, bispectrum multipoles, baryon acoustic oscillations, and cross-correlations with Planck's cosmic microwave background (CMB) lensing. Assuming the ΛCDM model, the analysis constrains the matter density fraction Ωm = 0.3154 ± 0.0089, the Hubble constant H0 = 68.34 ± 0.77 km s⁻¹ Mpc⁻¹, and the mass fluctuation amplitude σ8 = 0.686 ± 0.027 (equivalent to S8 = 0.704 ± 0.031). The results show a 4.5σ suppression of cosmic structure at low redshifts compared to the Planck ΛCDM concordance model. The study explores whether this tension can be explained by the recent DESI preference for dynamical dark energy (DDE). The BOSS data, combined with DESI BAO and PantheonPlus supernovae, do not show a preference for DDE, but the same ~10% suppression of structure is observed, with dark energy consistent with a cosmological constant at 68% CL. The results suggest that either the data contains residual systematics or more model-building efforts are needed to restore cosmological concordance. The paper also discusses the implications of the σ8 tension and the potential for new physics models to explain it. The analysis uses a combination of BOSS clustering data, DESI BAO, and supernovae data, and finds that the σ8 tension remains even when different subsets of the data are considered. The results suggest that the σ8 tension is not a prior effect but is present in the raw χ² statistic. The study also finds that the DDE model does not resolve the σ8 tension in the BOSS galaxy clustering data. The paper concludes that the σ8 tension is a significant issue in cosmology and that further research is needed to understand its origins.This paper presents a new perturbative full-shape analysis of BOSS galaxy clustering data, combining the galaxy power spectrum, bispectrum multipoles, baryon acoustic oscillations, and cross-correlations with Planck's cosmic microwave background (CMB) lensing. Assuming the ΛCDM model, the analysis constrains the matter density fraction Ωm = 0.3154 ± 0.0089, the Hubble constant H0 = 68.34 ± 0.77 km s⁻¹ Mpc⁻¹, and the mass fluctuation amplitude σ8 = 0.686 ± 0.027 (equivalent to S8 = 0.704 ± 0.031). The results show a 4.5σ suppression of cosmic structure at low redshifts compared to the Planck ΛCDM concordance model. The study explores whether this tension can be explained by the recent DESI preference for dynamical dark energy (DDE). The BOSS data, combined with DESI BAO and PantheonPlus supernovae, do not show a preference for DDE, but the same ~10% suppression of structure is observed, with dark energy consistent with a cosmological constant at 68% CL. The results suggest that either the data contains residual systematics or more model-building efforts are needed to restore cosmological concordance. The paper also discusses the implications of the σ8 tension and the potential for new physics models to explain it. The analysis uses a combination of BOSS clustering data, DESI BAO, and supernovae data, and finds that the σ8 tension remains even when different subsets of the data are considered. The results suggest that the σ8 tension is not a prior effect but is present in the raw χ² statistic. The study also finds that the DDE model does not resolve the σ8 tension in the BOSS galaxy clustering data. The paper concludes that the σ8 tension is a significant issue in cosmology and that further research is needed to understand its origins.