screenmirroring from MacBook Air to Sony smart tv using Apple TV box

I sent a previous request re screen mirroring. didn't post it properly I'll try again

I'm trying to screen mirror from a MacBook air to a Sony smart tv via an applebox.

the MacBook doesn't show the usual screen mirroring icon and says it can't connect to the apple tv

I tried to screen mirror an iMac using the same apple box to the same Sony tv and that worked fine

Disabling Trend virus software didn't seem to help with the MacBook

Any bright ideas for doing this mirroring ?