Cannot run asynchronous tasks using .apply_async() if adding periodic tasks at the same time

[aprilahijriyan]

I don't really understand what's going on with this issue, if you uncomment the code below run the sample code again, and then add the task via the API, it will crash.

fastack-celery/examples/celery/app/main.py

Lines 14 to 21 in cd9e11b

	# FIXME: I don't know why, when I uncomment the code below
	# the task can't be called by .apply_async() (maybe blocked by another process?)
	# @celery.on_after_configure.connect
	# def init_jobs(sender: Celery, **kwds):
	# print("init jobs")
	# sig = say_hello.s()
	# sender.add_periodic_task(5, sig, task_id="say_hello_periodic_task")