ESP32_CAM with Telegram

Hi. I’m using my ESP32_CAM to interact with Telegram for taking pictures and motion detection feature.
The problem is that ESP32_cam cannot connect to “API.Telegram.Org” and i’m getting in Arduino serial monitor this error message : " DNS Failed for api.telegram.org".
My router DNS servers are 8.8.8.8 and 8.8.4.4.

Have tried connecting ESP32-CAM to a phone 4G shared connection and every thing is working flawlessly.
Please help on how to solve this issue.
Thanks.