Windows client, post image backup script

I have a Windows image backup configured to backup C;D; and set up the post image backup script, postimagebackup.bat to shut the machine down when completed - the job is not scheduled, I just run it manually whenever I want to backup the machine. Then I leave it running over night.

However, the script gets run after the C: while the backup of D: is still running and hence it fails.

How can I get the script to only run after all the disks are backed up? I was assuming the script was for the whole image job, not per disk

Server: 2.5.37, Client: 2.5.30, Windows 11 Pro