In windows, when you apply a look-up to a subject column, and choose a variant, first a query is done for the subject, and then the look-up is retrieved with any variant ON prefilters applied.
However, in universal, the look-up retrieval is combined with the subject query with a LEFT JOIN on the look-up table without any prefilters applied. (neither with a default subject or variant)
I have a case where this leads to row duplication and consequently non-unique PKs.
Was this behaviour intended/foreseen?
To solve my problem I would have to make a view instead of use a prefilter, but it would have been nice if a prefilter sufficed.