So, this is good news and removes doubts about the reliability of this disk.
I haven’t found much helpful for this specific errors and the firmware of the WD drive, so the pragmatic approach I would use, if fsck is not able to permanently correct the issue: Recreate the file system from scratch.
If there are only large files to be placed on the disks like videos, backups, etc. consider to choose a usage-type with a huge inodes-per-disk-space ratio like I’ve chosen for my 3TB Toshiba disks i.e. mkfs.ext4 -T largefile4 …. The usage-types are listed in /etc/mke2fs.conf.
Also the default reserved disc space for super-user activities is 5% by default which makes around 180-190 GB with your WD drives: A quite large (wasted) amount of disk space with 4 TB drives. You can influence this amount also using mkfs.ext4and the -m parameter.