Best-fit time-integrated energy spectra of GRB 190829A (blue) and GRB 180728A (red) in model space using joint spectral analysis with different combinations of detectors (see Table 1). Panel a: first pulse of GRB 190829A is modelled with a Cut-off power-law model. Panel b: second pulse of GRB 190829A is best described with a Band function. Panel c: first pulse of GRB 180728A is modelled with a Power law model. Panel d: second pulse of GRB 180728A is described by a combination of Band and BB functions. The shaded regions mark the 1σ contour for the corresponding best fit model.