make sure to consume your post data in your application
for example if you have a Django/python application
def my_view(request):
# ensure to read the post data, even if you don't need it
# without this you get a: failed (104: Connection reset by peer)
data = request.DATA
return HttpResponse("Hello World")
Some details: https://uwsgi-docs.readthedocs.io/en/latest/ThingsToKnow.html