Grove - Multichannel Gas Sensor + mkr wan 1300 or mkr wifi 1010

*Scanning for addresses works and I have found the right address 0x10;

According to the library examples, the default address is 0x04. So why do you think everything is OK if you get 0x10?

Have you change the Serial object to USBSerial in the example code (as I guess you connected your PC by the internal USB connection and not using an USB2Serial adapter on the hardware serial interface)?