Train doors at Rear M1 car were not proven closed. TC opened and closed a few times but fault persis ted. Staff (CCK) checked and confirmed Rear M1 car B1 door w as not proven closed. Staff feedback that there was no obstr ~~~~~ Depot found 1624 B1 door leaf weather strip worn, protruding and rubbing against saloon carbody, causing door intermittently unable to close. Weather strip replaced & door cyclic test ok. Train released on 23/01/2020.