WD portable drive not backing up new folders?

[slim33slim]

I have a WD portable hard drive I use to back up files once or twice a week. It appears that if I create a subfolder in a folder that is set to be backed up by the WD drive, the newly created subfolder is not automatically set to be backed up. That's not normal, right? Newbie here, be nice...

 

[PC eye]

Once you set one specific folder with any program as well as any scheduled backup any changes made later have to see the changes made with the program as well. The backups are simply made from what is seen in the main folder not any newly created sub folder until that is later specified and remains unseen until then.