${\mathrm{H}}_2\mathrm{S}$ in the presence of HCl precipitates II group but not IV group because :

${\mathrm{H}}_2\mathrm{S}$ in the presence of HCl precipitates II group but not IV group because HCl decreases the concentration of ${\mathrm{S}}^{2-}$.

The presence of HCl inhibits${\mathrm{H}}_2\mathrm{S}$ dissociation due to the common ion effect. The presence of H+ ion in HCl is a common ion to  ${\mathrm{H}}_2\mathrm{S}$ .Because of the decreased degree of dissociation of ${\mathrm{H}}_2\mathrm{S}$,  the concentration of  ${\mathrm{S}}^{2-}$ ion generated is minimal.