How to show the action icon that attach to a column

[Maple_Aikon]

I have an action that attach to a column. In table view, the column will hide data and show the action icon only. But when I change the action to attach to another column, the column shows data only. What the difference between these 2 columns, and how to show the action icon as default?

The action button display as default when attach to column B

But when I change the attach to column A, the table view will show the column A data, not the action button anymore

So, how can I change this behavior, make the column A show the action icon, not data?