TC reported 'A' SIde Cab door not able to latch and secure closed, TC assisting to hold the cab doorclosed. TC open and closed a few times at BSH SB but to no avail. ~~~~~ TC reported 'A' SIde Cab door not able t   Check and found 3565 A/s cab door screws over-tightened, causing door latch to be intermittently stuck and unable to achieve the desired overlap criteria. This led to the door opening by itself in mainline. Removed screws and tightened appropriately ensuring smooth latch operation. Serviced latch assembly additionally to facilitate smooth latch motion. Function test ok, tug test ok, no DIR/DMI lit. Done By: Kenneth, Ashwin 45111