This problem is happening again, and is happening every day.
Originally multiple servers were setup with version 188.8.131.52, or the version before.
Now they are all on 184.108.40.206
Users with websites on any server are unable to FTP into the /backup folder on each site (symlinked to /var/backup/<website>), getting permission denied error.
On all our servers, the /var/backup currently has these permissions:
drwxr-x--- 170 root root 4096 Nov 27 00:34 backup
To get FTP access working again to the backup folder, I have to do this on each server:
chmod 755 /var/backup
And appears each night the permissions are reverted back?