Search string on Date field behaves differently between Qlik Sense June and September 2018

In Qlik Sense June 2018 or earlier, it is possible to use different values in search strings of a Date field.

For example, with the above Date field, the following search strings may work:

1. >=43495<43500 (raw number)
2. >=30 Jan 2019<03 Feb 2019 (field format)
3. >=30.01.2019<03.02.2019 (default date format)
4. >=2019-01-30<2019-02-03 (ISO date format)

If the Date field is loaded directly from a QVD file, only (2) works. If it is loaded in a preceding load statement, then (1), (3) and (4) works but (2) doesn't.
However, since Qlik Sense September 2018, only field format (2) works in all date fields. This affects not only search strings in a filter pane objects, but also in Set Analysis expressions.  

Environment:

• Qlik Sense up to version September 2018

The behavior is caused by a defect fix (ID QLIK-83612) ("Timestamp formatting lost when performing a preceding load on a qvd file"). The fix is included in Qlik Sense September 2018.
It is an intended change that only "field format" (2)  is accepted for search strings of Date field as a result of this bug fix. The QIX Engine behavior change is also seen in Decimal points originally absent are present after upgrade to QlikView 12.30 or newer

Working as designed.

When composing a search string to use in filter pane objects or Set Analysis expressions, the search value should always match the date format of the Date field being searched.