Why is my agitator plate spinning after rinsing?

My washer has been making terrible and loud blender-like noises after the agitation cycle. I am waiting for a repair man to come out but I need to do laundry! I have run a diagnostic and nothing comes up. I ran just a rinse/spin cycle and found that the washer fills, agitates, drains then the agitator spins when it is empty creating this very loud noise. I can’t figure out what is wrong or if it is an easy fix. Please help. 2-3 year old Whirlpool top load washer.