Article continues below advertisementSydney Sweeney found herself on the wrong end of a cinematic knockout when her boxing biopic Christy collapsed at the box office - and OK! can now reveal why her buzzy prestige project faltered in the battered indie film market.Euphoria star Sweeney, 28, arrived at the Toronto International Film Festival in September with what looked like an awards season contender.Article continues below advertisementSource: MEGASydney Sweeney's 'Christy' movie flopped at the box office.