I recommend against using copy and paste for this type of task.
Use this script instead:
SetVariable [$ID; value: ItemSpecs::admItem_ID2]
Go to Layout ["Job Ticket" (JobSpecs)]
Set Field [JobSpecs::admItem_ID ; $ID]
Copy and Paste script steps have two issues that the above script avoids:
1) The referenced field must be present in order for the step to work. If the field should be removed from the layout, the script step silently fails to work.
2) Copy replaces any data the user may have previously copied to the clipboard with the data copied by this script step. Users become annoyed and confused when data they have copied mysteriously changes each time this script is performed.