When creating a new widget, the Group By filter is not working as expected. While scrolling through the options, the drop-down will randomly disappear. The search bar does not appear every time you click. When double-clicking, the search bar will sometimes appear but it might also disappear at random.
Release : 16.0.2
This Issue occurs when the user clicks multiple times on the Dropdown which another request is already running.
Perform a Single Click on the filter attributes and wait for the attributes to be displayed. The number of attributes could also be causing the list to show up late.