Most washing machines have a timer that prevents you from opening the hatch just after the washing cycle ends. Instad you must wait for the timer to go off, usually a minute or two, before you can open the hatch.
Why? Would letting the user open the hatch immediately after washing ends pose any safety or other issues?
Mine doesn’t do this, but it does do a few slow spins right at the end so that everything settles to the bottom. Maybe yours is also doing this by waiting?
Possibly.