We recently upgraded to Qlik Sense 2019 Patch 4 (qliksenseserver 13.32.7), and values return null when using subfield in a filter pane. This was working on the older version of Qlik Sense and continues to work in QlikView.
The Subfield function no longer works as expected, specifically within a filter pane.
Currently the expression returns a null in the filter pane (no values shown).