I've found some bugs related to the Tab Queries. I tested in previous versions and they've been present for a long time but the new Query Combobox makes the bug easily visible.
For instance, when you open the FindWIndow on a master record and set a query, the master records will be properly filtered. When you navigate to the detail and set a filter, the detail will be filtered. Once you navigate back to the master tab, the detail in GridMode will be filtered (expected) and the master records will be filtered as well.
However, when you open the FindWindow again you cannot see what is the filter anymore, this is inconsistent and might be confusing for some users. See the attached video for reference and the steps to reproduce.
For what I see in the code the FindWindow object is always recreated when you click on a detail tab but m_query reference is kept.