I2C working weird on Nano 33 BLE

Hi,
I am trying to connect my Arduino Nano 33 BLE to an external device through I2C protocol (namely, a Time of Flight sensor).
I have uploaded the 'I2C scanner' code to check the address of the ToF sensor, and the code returned in the serial a sequence like

Scanning...
No I2C devices found

Scanning...
I2C device found at address 0x48 !
done

Scanning...
I2C device found at address 0x3D !
done

i.e. a random sequence of 'no I2C devices found' and random addresses. Most weirdly, this behavior shows up even when the Arduino is not connected to anything!!!

I ask how to make the I2C protocol work properly on Nano 33 BLE.

Can you give a link to the sensor module ? (a link to where you bought it).
Do you have pullup resistors ?
How is the sensor connected ?

I think that the board does not have pullup resistors for SDA and SCL.

The board has 4k7 pullup resistors for SDA1 and SCL1 and those are connected to a few chips on the board. When you change the I2C Scanner to "Wire1", then they should show. If you change the I2C Scanner, please show it to verify that you have indeed changed every "Wire" for "Wire1".