Difference in Backup File Size
I don't think you're doing what you want to do. It looks like you're striping your backups across two paths, which means your backup is evenly split between the two locations.

I suspect that your actual backup size is not 3.5MB, but rather 7MB. The difference in size is most likely due to the local storage being quicker.

Per Ola Hallengren's documentation:


  If you specify multiple directories, then the backup files are striped
  evenly across the directories.


I would strongly suggest modifying this script to only write to one path, and then use an automated method to copy this backup set to another location.