Apple "Download your data files" won't download to my Mac
Using Safari either on my M3 MacBook Pro or Mac Mini (both running up-to-date Sequoia 15.5), I attempt to download the iCloud photo download .zip files I asked Apple to generate for me. The animated download icon appears, and up to about 75 MB of the multi-GB file loads, then downloading stops cold. Double-clicking on the file stub in my Downloads folder returns this message: "Safari can’t resume this download. The file “iCloud Photos Part 1 of 48.zip.download” doesn’t appear to be a valid download file." This happens with each of the data files Apple generated. Using Chrome yields a similar message. I've looked at every Safari and Mac setting that might seem likely to have an effect, I've cleared my cache, etc. Nothing changes. What's my problem?
MacBook Pro 14″, 15.5