First, the Atlantis, as well as all Maytags, spin while the tub is full. They do not drain first, rather they drain simultaneously with the spin. This is to keep soil from re-depositing on the clothes as the water drops thru them.
You need a new pump, as the new style pumps have a special insert to make sure they begin pumping and do not suds-lock as in previous designs. The new pump comes with the insert installed in the intake.
They had 2 style of pumps for this machine, so click on the one that closest resembles yours for pricing and info.
Style #1- Original design
Style #2- On later models