How to get NodeMCU with NTC showing the correct temperature (about 4 degrees off)

I’m struggling to get the NodeMCU (AZ-Delivery ESP8266mod F-12) working correctly with a NTC showing the correct temperature.
For that reason I wanted to know Explain NodeMCU GPIO voltage if the voltage tolerance would be an issue.

The temperature reading from the ESP is about 4.3 degrees to high. My study is 22 degrees C and HA is measuring 26.1 degrees C and slowly climbing.

I have connected as follows:
According to NTC Sensor — ESPHome. To prevent self heating, the voltage divider is turned on every 60s by a GPIO output

  - platform: ntc
    sensor: resistance_sensor
    name: $upper_devicename Temperature
      b_constant: 3950
      reference_temperature: 25°C
      reference_resistance: 10kOhm
  - platform: resistance
    id: resistance_sensor
    sensor: source_sensor
    configuration: DOWNSTREAM
    resistor: 10kOhm
    name: Resistance Sensor
  - platform: adc
    pin: A0
    id: source_sensor
    # Added:
    update_interval: never
      - multiply: 3.3

  - interval: 60s
      - switch.turn_on: ntc_vcc
      - component.update: source_sensor
      - switch.turn_off: ntc_vcc
      - logger.log: "Measure Temp"

  - platform: gpio
      number: GPIO5 #GPIO16 # Pin D0
      inverted: false
    id: ntc_vcc

Logging output:

22:15:47][D][switch:055]: 'ntc_vcc': Sending state ON
[22:15:47][D][sensor:109]: 'source_sensor': Sending state 1.60811 V with 2 decimals of accuracy
[22:15:48][D][resistance:039]: 'Resistance Sensor' - Resistance 9504.8Ω
[22:15:48][D][sensor:109]: 'Resistance Sensor': Sending state 9504.76172 Ω with 1 decimals of accuracy
[22:15:48][D][ntc:026]: 'Irrigation Controller Temperature' - Temperature: 26.1°C
[22:15:48][D][sensor:109]: 'Irrigation Controller Temperature': Sending state 26.14746 °C with 1 decimals of accuracy
[22:15:48][D][switch:016]: 'ntc_vcc' Turning OFF.
[22:15:48][D][switch:055]: 'ntc_vcc': Sending state OFF
[22:15:48][D][main:167]: Measure Temp

I’ve tried to understand the calculation at NTC Thermistor Resistance Calculator V2.0 and the resistance should be 11441Ohm. I found similar threads here 10k NTC Thermistor - Not Reading Resistance Properly? - #7 by ideal2545 and try to learn from there.

I hope some can explain me how to get correct the measurement.

thx for reading.

Anyone who can explain?