How can I fix this problem?

No there is only 1 belt as you would see if you just looked underneath where the belt is. Agitator direction is governed by reversing the motor electronically. You should be able to tell from the sound of the motor if it is pulsing both ways. If it is but the agitator locks up on the reverse swing then it is a clutch or brake problem. If motor runs one way, then silence for a second or two then runs again, it will be an electronic fault i.e. faulty timer or module. Not easy to find this fault without test meter and knowledge. May be better getting some one out to check it.

Lincoln Appliance NZ
May 2017