Here is the image
Oh yeah, this is FP 10
Sounds like you need to commit the record before the related data will appear. If so, then clicking a blank area in the layout will also cause the data to appear.
You might want to use a script trigger on the DPP Number field that runs a script with the commit record step to automate the appearance of this description text on your layout.
Do I do that by right clicking on the field, selecting set script triggers?
What do I select there?
I deliberately didn't specify that detail as it depends on how that number is first entered/created in this field and when I look at your first screen shot, I confess to a bit of confusion here.
Your first post and the diagram both show that the DPP number is created in the Plating Calc table. How then can it link to an existing record in the DPP List table in order to display a description? If the values are first created in DPP List, this field can be set up as a drop down list or pop up menu of values from the DPP List table--but that doesn't seem to be what you have set up here.
I created a trigger with a commit record action and that seemed to take care of it.