EDIT: I have more information in a new post below.
Hello.
I'm trying to build an app that has a simple gallery with a list as the data source. The data source only has one extra column except for the defaults, Margin. Margin is a numeric column with a default value of 20.
When I build the gallery from the data source, the Margin column isn't available.
Here are the columns in the list:

And when I add the data source, I only get Title as a data card. If I manually add a label, this is what happens:
And likewise, when changing the Text parameter:
How come I can't use the Margin column in my gallery?