lisyarus

Encountered this in 1.21.6. Never seen it in prior versions (1.19.8, 1.20.10, 1.20.12) for about 200 hours of playtime. This is vanilla. The seed is 90165327, only found the affected chunks after travelling for quite a while (5000 blocks) and returning. One of the affected chunks is at coordinates -1832, 124, 893. The /debug chunk relight command worked.