Gas metallicity Z_gas as a function of stellar mass M_⋆ at z = 12, 10, 8, and 6. The solid lines represent the mean values for CDM Ref (blue), CDM HR (purple), and CDM LB (green), while the darker (lighter) shaded regions represent the 1σ (2σ) standard deviation. Grey symbols refer to JWST results described in Nakajima et al. (2023, stars), Curti et al. (2023, pentagons), and Tacchella et al. (2022, triangles). Globally we find that our simulations are in good agreement with JWST observations.