biweekly: happening or appearing every two weeks or twice a week. Cambridge Dictionary
In the following news articles, What the author mean by "bi-weekly"? if it is mean "two weeks" or "twice a week", Why doesn't they use a specific term to make it clear for readers?
Niantic was, by its own admission, caught off-guard by the sheer popularity of Pokemon Go, but it has pledged to continue supporting the game with bi-weekly updates. BBC
She's lived on Brexit Street for 18 months now but knows no-one. She only goes out to walk to her bi-weekly English lessons or to the drop-in centre round the corner. BBC