Pluggin allowed to filter posts for keywords only once?

Hi!

Is the pluggin only allowed to filter a post once?

I created a post I made for a test, which contained all possible categories my site uses. I launched the pluggin’s action with a few entered keywods, It worked and the categories appeared in the post, but once I tried entering more keywords in the pluggin settings, the test post couldnt be detected and filtered once again. Is this on purpose or am I missing something?

Thank you!