I have the same problem! When the sensor is connected, the readings differ from the real ones.
The SHT20 sensor reads both temperature and humidity. If I read only one value (either temperature or humidity), then the readings are correct, but if I read both, then the temperature is too low and the humidity is too high!

I understand that you can write a correction, but:
- this is not correct - after entering the coefficient, I try to breathe into the sensor and it shows me a temperature of 70°C;
- when connecting any one sensor, the readings are correct, which means it can work without corrections!
my code:
sensors:
- name: 'Температура'
scan_interval: 5
slave: 1
scale: 0.01
address: 1
data_type: int16
input_type: input
unit_of_measurement: °C
device_class: temperature
state_class: measurement
precision: 2
- name: 'Влажность'
scan_interval: 5
slave: 1
scale: 0.01
address: 2
data_type: int16
input_type: input
unit_of_measurement: '%'
device_class: humidity
state_class: measurement
precision: 2