Deleting/Removing multiple properties from the AW property list only works with the keyboard Delete key. Right-click Remove Properties only removes 1 property at a time.

repro:
Create a Cube
Add 3 properties (ex: Transform PRS)
Select the first -Shift- the last property
With all 3 properties selected...
Right-click and select "Remove Properties"... only the last property is removed. (bug)
... or...
Hit Delete on the keyboard... all properties are removed, expected behaviour