They are the only resistors on the board that drift. Because they are a high precision resistor and likely are a different brand/series, they just happen to be more susceptible to Sulphur degradation.
In case this is of interest to someone, it looks like I have a long-term fix for the suspension rod dampers in the current model Fisher & Paykel top loaders which I can share. It's a bit involved and only suitable for those doing a lot of back yard washer repairs.