Remake feature not working

There was a Rengar which disconnected at the start of the game. At 3 (three) minutes I attempted the /remake command. It said "/Remake is only available when a player has failed to connect". My ally Kayle also reported the same message. I constantly tried but it was not working. It was now 8 (eight) minutes in the game and the Rengar reconnected. The damage had been done and we loss. Please fix this issue. This is crippling.