change of behaviour for empty kwargs with `public_send`

Question

I made an update of my Gemfile and since I've a spec that failed.

Here is the code:

module V1
  ##
  # Pusher job
  class PusherJob < BaseJob
    queue_as :default

    ##
    # Call V1::PusherLine#notify_now
    def perform(pusher, delivery_action, *args, params: nil, **kwargs)
      klass = pusher.safe_constantize
      handler = params ? klass.with(**params) : klass.new

      handler.public_send(delivery_action, *args, **kwargs)
    end
  end
end

RSpec.describe V1::PusherJob do
  subject { job.perform(double_pusher_string, delivery_action, *args, kwargs) }
  let(:job) { V1::PusherJob.new }
  let(:kwargs) { {} }

  describe '#perform' do
    let(:double_pusher_string) { double(:pusher_string, safe_constantize: double_pusher_klass) }
    let(:double_pusher_klass) { double(:pusher_klass, public_send: true) }
    let(:double_instance) { double(:double_instance) }

    let(:delivery_action) { Faker::Lorem.word }
    let(:args) { Faker::Lorem.words(number: 4) }

    context 'without params' do
      it 'forms correctly the method' do
        expect(double_pusher_string).to receive(:safe_constantize).once
        expect(double_pusher_klass).to receive(:new).and_return(double_instance)
        expect(double_instance).to receive(:public_send).with(delivery_action, *args, **kwargs)
        subject
      end
    end
  end
end

Error I got it

1) V1::PusherJob#perform without params forms correctly the method
     Failure/Error: end

       #<Double :double_instance> received :public_send with unexpected arguments
         expected: ("dolorem", "rerum", "et", "et", "quia", {})
              got: ("dolorem", "rerum", "et", "et", "quia")
       Diff:
       @@ -1 +1 @@
       -["dolorem", "rerum", "et", "et", "quia", {}]
       +["dolorem", "rerum", "et", "et", "quia"]

When I display arguments passed to public_send, kwargs is correct with the value {}. There is here a behaviour that I cannot catch.

BUT if I change value of my kwargs to a non-empty hash, it works.

I cannot find where this changes come from. Any idea?