The purple slide release tab are inside the rail and the unit can't be pulled out or push in. I managed to get some strings looped into the purple release tabs and can pull them, but still can't get the drawer to move in or out.

The internal railway might be a little bit off track to cause this issue. Customer might use a screwdriver and hammer to hammer onto the 2nd section of railway in order to push that railway backward a bit that it should be go back to the right track.