Why won't Frontier (imdb = http://www.imdb.com/title/tt4686698/) show up in my calendar when I select 'follow it", . I see it in your datsbase when I search for it?
Frontier premiered on the Canadian Discovery Channel network and the last episode aired in December, I think this is why :)
TVMaze doesn't track repeats or premieres in other country.
Frontier aired between November and December 2016 so if you look back at those dates you'll see it.