Star-forming main sequence in the Flagship (left) and GAEA (right) simulations (models m3 and ECLH, respectively) at 0.4 < z < 0.9 (top) and 0.9 < z < 1.8 (bottom), color-coded by the Hα luminosity, which essentially correlates with SFR. The red lines correspond to the compilation of observational data presented in Popesso et al. (2023). The contours encompass 50% and 75% of the galaxy distribution for Hα flux-limited sample (solid lines) and for the sample without any limit (dashed lines).