I have heard of this happening.
In fact, Freddie Mac did a study late last year that found that 15.4% of houses in majority Latino tracts and 12.5% in majority Black tracts appraise significantly below market value (so, yes, the person in the comments who said Latinos have it even worse is justified.
There's another issue here. In purchase transactions, Black and Latino applicants get lower appraisals. As in, if the *borrower* is not white the appraisal, which their mortgage is based off of, gets lowballed. If your appraisal is below the contract price, you are likely not going to be able to purchase the home. Or you can negotiate, but that drops property values for everyone.
Unless, of course, it's for property tax, in which case be sure that Black-owned houses are suddenly worth more.
And here, for the commenters who somehow think this is a one off, is another example of this from December 2021. This is an affluent, mostly white area in Northern California, and the appraisal rose by nearly half a million when they whitewashed the home. The original appraiser valued the home "as if it was in a Black neighborhood."
A Black purchaser had a white friend pretend to be her brother and hid not just her race but her gender from the appraiser. This more than doubled the value.
https://www.freddiemac.com/research/insight/20210920-home-appraisals
https://www.cnn.com/2021/12/09/business/black-homeowners-appraisal-discrimination-lawsuit/index.html