Best-fit SEDs of ID9094 with fixed dust temperatures, providing the first hint of an AGN scenario in this work. Top panels: Best-fit SEDs without an AGN component. Bottom panels: Best-fit SEDs with an AGN component. The 3σ upper limit from NOEMA 1.3 mm, the deepest FIR photometric constraint, is highlighted; it plays a key role in shaping the FIR SED and constraining the lower limit of T_dust. The FIR photometry has been corrected for CMB effects. We show three representative T_dust during the fitting with and without an AGN component, which results in the predicted 1.3 mm flux exceeding (a and d), equal to (b and e), and below (c and f) the observed 3σ upper limit. Panel d shows the fit with an AGN and T_dust = 40 K, which slightly exceeds the 3σ limit but is not ruled out given the model degeneracy and observational uncertainties (see Sect. 3.2.1). Without an AGN, the SED fitting requires T_dust  ≳  110 K. This value significantly exceeds the typical T_dust ∼ 40 K observed in REBELS galaxies at similar redshifts (Sommovigo et al. 2022), and may indicate additional dust heating mechanisms such as AGN activity. In contrast, including an AGN component (bottom panels) allows acceptable fits with T_dust as low as ∼40–60 K, similar to AGNs and/or quasar host galaxies at z > 4 (∼40 − 100 K; e.g., Walter et al. 2022; Tsukui et al. 2023; Tripodi et al. 2023; Decarli et al. 2023), supporting the presence of an AGN in ID9094.