I added an entity reference field to a line item within commerce. 

Target is user, entity selection is done through a custom view. The view populates the values of a date field within the actual user entity. The preview works as desired, the field has 3 values and those 3 get shown in the views preview. 

However looking at the add to cart form it always shows just the last value of this multiple value field. Why are not shown all 3 values in the add to cart form? 

Another question: I just checked it with another regular user account and it gets more strange: The second option (label) gets produced but the field content is not displayed at all.