clip won't play with the rest of the video but plays separately

Hey, I have Premiere Pro CC2017, and I recently downloaded some templates for a video I'm editing, but when I add the template sequence into the video, it won't play with the rest of the video, but when I double click it to edit it alone, it plays just fine. I don't know how to fix it, and I can't find any solutions online. if I could get some advice, it'd help. Thanks!