Diagnosis
The washer's motor or drive system is failing to engage the agitator. On these models, a worn coupler between the motor and transmission can strip, or the motor itself can have issues.
How to Fix It
Unplug the machine. Tip it back (get help, it's heavy) to look underneath. Inspect the plastic motor coupler—it's a three-pronged piece connecting the motor shaft to the transmission. If it's cracked or the ribs are stripped, it won't transfer power. It's a cheap, common failure part.
If That Didn't Work
If the coupler looks fine, the problem could be the motor brushes, motor control board, or the transmission itself. These are more involved repairs.
Heads Up
The coupler is designed to fail first to protect the more expensive motor and transmission. Replacing it is a standard DIY fix, but you have to disconnect the motor to do it.