Vostro 5490 RAM upgrade problem - My laptop do not recognize the new RAM full clock

Hi guys. I bought a Lenovo RAM of 16GB 2666 Mhz for upgrade. I removed the old Dell memory of 8GB 2666MHZ. The system recognized the 16GB RAM with a speed of 2400 MHZ. Is there anything to be done? The notebook's manual states that it can be used up to 16GB 2666 MHZ. Sending CPU-Z image from Lenovo memory. Thank you for your help.