IFF you mean that, AFTER it runs, and is OFF, it successfully
drained out all or most of the water out, and it still looks OK
after say 5 minutes, but then a few or several hours later it
will have a lot of water in it, then you have a problem with the
water shut-off valve, which is operated by a solenoid in the
machine. The solenoid isn't very likely a problem - it's just
not closing off the water completely, sort of like a leaky
faucet. The longer time period, the more water there wil be.
The valve/solenoid is one unit, and not very hard to replace, but
you'll have to pull off the front kick panel and get the unit out
of the cabinet where you can get at the underside easily. It's
definitely a diy job unless something unexpected pops up.
While you're in there, if you're connected to the water supply
with rubber hose, you might want to replace that too, along with
the drain hose if it's rubber.
Be CVERTAIN to unplug it before you touch it! There is exposed
voltage inside the kick panel.