Strange output, but why and how to solve it

Projects Programming
5

I'd be inclined to try testing it with a sketch that just has what it needs to compile this:

    sensors.requestTemperatures();
        
    sprintf(payload,"{Temp_buiten_camping:%d,Temp_binnen_camping:%d}",round(sensors.getTempCByIndex(1)*10),round(sensors.getTempCByIndex(0)*10));
    Serial.print(payload);