The current bor mainnet snapshot is borken. Tried both with your script and manually. The checksums are fine.
tar -I zstd -xf “bor-mainnet-snapshot-bulk-2023-10-12.tar.zst” -C ~/chaindata
/stdin\ : Read error (39) : premature end
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now
Reupload, please.