Focus Keyword On Category Page Title

Hello,

I’am trying to use %%focuskw%% for page title. I don’t want to use long category names. So I need to use focus keyword. I will use it on page title.
U edited snippet as %%focuskw%% %%sep%% %%sitename%%. On yoast plugin preview it seems as work. But when I open categry page it doesn’t appear.

Why ?

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