@everetra - It’s quite surprising to learn how the washing machine is tripped by the threshold voltage. I always thought that it used a timer mechanism of some sort to know when to change different phases or cycles.
Since it’s dependent on slight voltage variations and not a timer however, I suppose it could malfunction if anything happened that threw the voltage off by even a little bit.
An electrical spike across the line might do that. It might be wise to have some voltage protection for your appliance in that case too.