I'm not sure why it is not showing as I just tried it and it is working for me.
If option 2 is currently selected, just select it again to force it to apply the change a second time.
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The actual key image is in a file called gameclient\ui\custom\assets\textures\buttonimages_03.tga. That file is loaded from the assets.xml file which is not something that is changed when you switch between the various options in the UI.
The image reference for it is defined at the top of the gameclient\ui\custom\realmkey.xml file when you select that option. This file is changed when you select the key options. The xml code near the top of the realmkey.xml file that defines the button looks like this:
<!-- Labyrinth Key Button Images -->
<ImageAreaTemplate>
<Name>ImageArea_Map_Key</Name>
<TextureName>buttons_03</TextureName>
<Size>
<X>20</X>
<

>10</Y>
</Size>
<TopLeft>
<X>220</X>
<

>55</Y>
</TopLeft>
</ImageAreaTemplate>
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The only other thing I can say offhand is to make sure you are running the latest version of the UI which is 1.94 v4.03.
You can check to see which version you have by opening the Main Menu (click on far right button in the StatusIndex window). The version you are using will be displayed at the top of the window along with the address of my website.
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