Slow process on imdb_search

I have a collection that's created using a imdb_search keywords. The result is ~4000 entry. I'm trying to understand why is so slow on missing movie. Kometa find right away the matching IDs (showing it in the script) but that start to process each one of the missing movie. Why is it processing missing one?
What it is doing there? I don't have any operation going on missing movie, no radarr configured or metadata operation