I've worked in the housing industry. The unfortunate reality here is that it's really hard to tell if discrimination actually happened because appraisals are a

I've worked in the housing industry. The unfortunate reality here is that it's really hard to tell if discrimination actually happened because appraisals are all fluff anyway and that kind of a difference between two different appraisers isn't at all surprising. It's quite possible they got a conservative appraiser who didn't understand the neighborhood and market and played to caution. You'd be surprised how often this happens. Just removing personal effects from the home tends to up the appraisal rate by itself. The only way to really know if this is discrimination is to have the same appraiser appraise a model match of the house itself on a similar timescale with someone different answering the door. But you almost never get the chance to run the same experiment twice.