Al final puse la temperatura como estaba,la nueva placa del ISS con el nuevo sensor de temperatura ya hace el calculo perfectamente según me comento Ryan,la placa viene con el firmware 2.5.
No do not make the correction. If you purchased a new ISS from me then the transmitter's firmware ALREADY makes the correction for you for the SHT31. Making a correction would be a mistake. The only time you want to make a correction is if you have an older ISS with firmware 2.0 or less and you replace the T/H sensor.
Saludos