Apologies for my lack of clarity in describing what I am observing. Hopefully the following will make it clearer:
1) I click the Event containing all the clips and select a clip.
2) I open Key Word with Command+K and type in "Scene 3" <Enter>
3) On the left a key word :Scene 3" appears and if I click it then my so marked clip shows to the right
4) Next I mark all other clips, with their respective Scene numbers (1 to

5) I now discover that I made mistake and a file (clip) is incorrectly marked as Scene 3, but should be Scene 1, so I select it and open Key Words and delete "Scene 3" and add "Scene 1" and press <Enter>
Now I have found that the file lists are only refreshed when you freshly select a key word on the left Browser pane, so I click on another Key Word in the Browser pane, then back to clicking Scene 3 in the Browser pane.
The clip that no longer has "Scene 3" as key word still shows when the Browser pane is key word Scene 3, even though clip is ONLY key worded as "Scene 1".
I then quit and restart FCPX, but the situation is unchanged.
I could paste a screen shot, if that would be helpful.
Note: I didn't delete the Key Word from the system, I just deleted it being assigned to a file/clip.
Thanks for looking into this. I appreciate it.