@JC-25070522-0
The Formula you mentioned for the Display Name is correct.
DataSourceInfo([@the list you are sourcing from],DataSourceInfo.DisplayName,the name of the column from the source list)
But this is just a Dynamic way of getting the name from the list, if you use "Column Name" this would work too as long as you input it as a text, and this doesn't count for the missing data.
The reason for the missing data for missing data is because of the update property.
{Id: ToolSubcategoryDropdown.Selected.ID,Value:ToolSubcategoryDropdown.Selected.Name}
property.
Try this. If this doesn't work, please share the formula for the Items property of the "Tool Sub-category" and update property of that columns data card.