Teammates invisible in match

Did a team builder match with 2 friends. When the game launched, they were in the match, but did not show up on my screen or mini map. All I could see was Maokai's boxes and wards from Taric. Otherwise they were completely invisible to me. They also did not appear in the scoreboard and when they got a kill, it didn't register on the team kill count. I have a screenshot, if needed, but doesn't look like I can post it here.