Integrate an SHT41 onto a working ESP32-wroom 32 board

Hi everyone,
perhaps someone can help me out:

I’ve got an “empty” ESP32 board up and running in HA. Nothing was/is connected to it and it shows up in HA just fine.
Now i wanted to add an Sensirion SHT41 sensor to it. I wired it to GND, 3.3V as well as SDA and SCL to pins 21/on the board.

In the ESPHOME yaml config i added

i2c:
  sda: GPIO21
  scl: GPIO22
  scan: true

sensor:
  - platform: sht4x
    temperature: 
      name: "Temp"
    humidity:
      name: "humi"

Wenn i compile it and it is put onto the board, i get the 2 sensors shown in HA but they have no data.

In the ESPHOME log in HA i get this:

[16:27:21][I][i2c.arduino:096]: Results from i2c bus scan:
[16:27:21][I][i2c.arduino:098]: Found no i2c devices!
[16:27:21][C][sht4x:050]:   Address: 0x44
:
[16:27:34][D][sht4x:080]: Sensor read failed
[16:27:34][W][component:237]: Component sht4x.sensor took a long time for an operation (1004 ms).
[16:27:34][W][component:238]: Components should block for at most 30 ms.

Am i missing something here?
Thnaks for any suggestion.