Problem with 8-Channel 12-Bit ADC / I2C adress and no input value

I use 8-Channel 12-Bit ADC for Raspberry Pi (STM32F030) with Pi3B.
On your website the I2C address is shown as 0x04(default) but my pi tells me that it is 0x08 (with i2cdetect)
With 0x04 the python example program gives me an error message with 0x08 it works.
I have now 2.5 V connected to AD1 and GND but the example programm shows me 0 for every channel and I don’t understand why? I only run the example program with the changed i2c adress.
Maybe you can help me? Thank you in advance.

Hi guys, due to the epidemic, the chip used on this product has been modified from STM32 to MM32, so the I2C address has also changed - the address has been changed from 0x04 to 0x08.
Please check which chip you received before using this product, if you are using MM32, please change the I2C address 0x04 to 0x08 in the file.

thank you for the answer,
I changed the adress in and
The communication works now I think (there are no error messages) but I still measure no voltage on the adcs and I don’t understand why?
If I execute I get 0 for every channel although there is a voltage of around 2.5 volts betwenn A1 and GND ? I can measure the voltage on the seeed card with multimeter

If i run I get the right values for channel 1 but not for and