Error on the server took too long to shut down and was killed, how to solve?

Question

Django

There is a view that sends data to the mail. On the local host (0.0.0.0) with debug=True and False it works well, but for some reason everything broke on the server and now it loads for a very long time and as a result 500 error.
And here's the miracle:
Application instance wait_for=._call_check_cancel() at /usr/local/lib/python3.7/asyncio/futures.py:351, ()]>> for connection took too long to shut down and was killed.

Answer 1

Cannot assign requested address

Hints that you have problems with setting up the network.