I added the highlighted to my UDF


double REAL_enthalpy(cell_t cell, Thread *thread, double Temp, double density, double Pabs, double yi[])
double Temp2 = C_T(cell,thread);
double Pabs2 = C_P(cell,thread);

double cp = REAL_specific_heat(cell, thread, Temp2, density, Pabs2, yi); /* Cp = 1004.16 J/(Kg K) IF Temp < 500 Kelvin*/
double h = Temp2 * cp;

if (Temp>500){
Message("Enthalpy Temp Warning, Temp: %f K P: %f Pan", TempPabs);
Message("Enthalpy Other Monitors, Temp2: %f K P2: %f Pan", Temp2, Pabs2);

return h; /* (J/Kg) */

As I was suspecting, fluent is retrieving by default the total pressure and total temperature at least in the entropy and enthalpy functions (see the attached image). Unfortunately now I have the opposite issue and the temperature tends to 0 Kelvin. I have attached the contours of dynamic temperature and static temperature. It doesn't go to 0 because I have limited the minimum temperature to 200 Kelvin. For some reason that I cannot understand there are many extrange interactions at the inlet.