bug report plz fix riot

one of my friend got into low priority queue but he was still playing with me last game we were playing league of legend rank and sadly we lost, and afterwards the game we both left to do something else, but when we both come back and wanted to enjoy a new rank game, it suddenly said low priority queue, it seems to be a 15 mins queue dodge but we were away 15 mins ago, so we needed to wait 15 mins for a rank game for absolute no reason what so ever. riot help us.