Can’t «Display as Table» in Detail View

I have a table (Aufträge) with 3 Related columns to 3 different tables. In the Layout of the Detail view of the Aufträge Table I can set the Display of 2 of these related tables to “Table”. But the third table only has the options to display as «Auto», «List» or «Dropdown».
Also, I am sure that when I created this layout it was possible to display the third table as «Table».
Does anyone know what the problem could be?

Maybe you have allow multiple selections turned off - which makes table view unavailable: