ActiveSupport::CurentAttributes surprise

example.rb

class JwtCurrent < ActiveSupport::CurrentAttributes
  attribute :jwt
end

# in api_controller.rb
def some_action
  JwtCurrent.jwt = "something"

  future = Concurrent::Future.execute do
    puts "*" * 50
    puts JwtCurrent.jwt #=> nil
    puts "*" * 50
  end

  result = future.value
  render json: result
end