I'm using SharePoint Online.
In the "Contact" list have a calculated column with this formula:
IF([Active],[Last Name]&" "&[First Name],"")
This formula is working fine.
In another list I have a lookup field referred to this column. But when I try to add a new item with the InfoPath form, it shows all values (with empty values too) in the dropdown.
Has something changed since this post https://sharepoint.stackexchange.com/a/206144/20605 ? Or am I doing something wrong?