Ruby on Rails: Why does my array set contain null, passing my null checker?

I have a code that looks like this:

*movie_requests is a scope

def self.records (producer_id = 0)
  actor_list = Array.new
  movie_requests(producer_id).find_each do |studio|
    actor = studio.actors.pluck(:id).uniq
    if (!actor_list.include? actor) && (!actor.nil?)
      actor_list << actor
    end
  end
  return actor_list
end

Originally in the database, it has these actor ids:

[[12305], [3749], [1263], [], [], [1263], [], [12305], []]

.pluck and .uniq makes redundant ids from each studio distinct however [] still exists:

[[12305], [3749], [1263], []]

Why doesn't my && (!actor.nil?) condition catches the null ids and make it a distinct object?