cant cast from chromebook to samsung series 7 smart tv

Hi
not sure if correct spot to post but here goes. I got a new ASUS C214m chrome book for Christmas. I wanted to cast a website on to my TV to stream a comedy from the web. clicked the 3 dots and then cast. All the ASUS picked up was my sky Q with the message available for specific video sites. There was no option to search for devices.

Went into process of elimination mode. Checked an MKV file I had on an sd card on the ASUS, still just picked up the sky box. Tried my android phone and my android tablet both picked up the smart TV without a glitch straight away and even played the website i was trying to play on the ASUS.

Checked all the settings I could on the ASUS to mirror the android devices. Everything checked out. Wifi on same network blue tooth on etc. Does Chrome not play nice with Samsung or am I missing something