Ok so this might not be correct but I am 90% sure the a320 family may be outdated and cannot support a logo on the bottom (like the SWA 737-700) but it might just be missing
Aircraft with older models like the 737 and a320 family in infinite flight use the old livery system. Whatever you paint on one side, the other side will be mirrored. So asymmetrical shapes like the LATAM logo are impossible to add on the bottom of older aircraft models. Newer aircraft models like the 757 for example use a new system that makes it possible for you to add asymmetrical shapes to the bottom of aircraft.