Ds18b20 returning wrong CRC

Other Hardware Sensors
3

Hi, in fact I bought them on Amazon. But could a counterfeit sensor give a right temperature and wrong CRC? The reading seems okay, just touching it with the finger causes it to rise immediately and then go down again when I release it.

This is the relevant part of the code:

if (Read_bit())
        {
            if (ds18b20_start())
            {
                Write_byte(0xCC);                 // Send skip ROM command
                Write_byte(0xBE);                 // Send read command
                for (int i = 0; i < 9; i++)
                {
                    scratchPad[i] = Read_byte();
                }
                Serial.print("Scratchpad: ");
                for (int i = 0; i < 9; i++)
                {
                    Serial.print(scratchPad[i]);
                    Serial.print(" ");
                }
                Serial.println();
                //bool test = crc8(scratchPad, 8) == scratchPad[8];
                Serial.print("Calc CRC: ");
                Serial.println(crc8(scratchPad, 8));
            }

            temp = ReadSensor() / 16.0;
            Serial.print("Temp: ");
            Serial.print(temp);
            Serial.println(" ºC.");
            Serial.println();
        }