@AdrianChang - thanks for providing an explanation but unfortunately I do not understand any of it. On reading your code however, I think the below is what you're trying to do:
AddColumns(
Filter(
[@'[New] Loan Extension Submission'].'Machine(s)/ Item(s)',
Value in Filter(
'[New] Machine/ Item Status List',
'Customer Account No.' = DataCardValue1.Text And Status.Value = "Done - Loan"
).Title
),
'Code + Name',
Concatenate(
Id,
"-",
Value
)
)
Note: If you make any change to the Items property of a ComboBox, often you will need to "reselect" the field you want from the Primary text and Secondary text menu (even if you're reselecting the same field). If this does not work, try applying the formula to a new ComboBox control.