How are you backing up the SQL Server’s databases? Are you using the BACKUP DATABASE command or are you just copying the files from the SQL Server to the other server?
What are you using to backup the server’s files to the other machine?
If you are just copying the SQL database files that isn’t going to do anything for you. You need to use the BACKUP DATABASE T/SQL command to backup the databases to disk, then move those files to the other server.