Using my two screenshots and values, note:
 1. Using Keyboard: I have 'A' selected and type a single 'W' to change my selection and hit enter. The next drop-down will still display at the width you see for the original A selection.  It will not be until the next drop-down that it resizes correctly.
 2. Using Mouse: I have 'A' selected and select the 'WWWW...." from the drop-down with my mouse.  The drop-down will appear correctly the next time.