Hi @mlalfor77
Could be that the splines on the agitator have worn down and it is slipping on the transmission shaft. Worst case would be if the corresponding splines on the transmission shaft have also worn down as well.
Here's a [https://www.youtube.com/watch?v=c9TvsEr1Kwc|video] that explains how to replace it. The agitator part number shown in the video i.e. W11550891 is the one for the agitator used in your model washer.
Search online for [https://www.google.com/search?client=firefox-b-d&q=W11550891+|W11550891] to find suppliers that suit you best. (examples only)