The tar is stops if it cannot read some files other owner and mode 0x400:
tar: Can't open `.ftpquota': Permission denied
tar: Error exit delayed from previous errors
On previous OS version the archive was created successfuly thouth errors.
# tar --version
bsdtar 3.2.1 - libarchive 3.2.1 zlib/1.2.8 liblzma/5.2.2 bz2lib/1.0.6