Arrived on site client stated they shower was backing up again. Upon inspection it doesn’t appear to be the same issue which was hair the last time. This time shower only seemed to back up when I high volume of water was being used then would immediately go down when water stopped being used. Upon camera inspection client has old cast iron under the home that wasn’t in the best shape. There were no visible clogs in the drains as everything that was ran was draining fine. Client pull like senior tech out to give best possible solution for the situation.