we take vps backups for server recovery in case of main file system/os problem not for clients file system, Clients needs to make their own backup policy and take backups of their own.
subdomain already added so it does'nt matter whether you had issue while adding subdomain, i check this domain at different location and found okay. I also suspect dns cache issue .
MSSQL server 2 had problem for few minutes, the server resources (CPU and Memory ) were overutilised and the problem resolved immediately
Please check your sites now