Answer by Trilla for Nginx: What is causing this 301 redirect?

I'm still not sure how to fix this completely, but when I take out

return 301 https://$server_name$request_uri;

and run curl -I -L http://www.myapp.com/ I get

HTTP/1.1 200 OK
Server: nginx
Date: Tue, 05 Mar 2019 13:33:42 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 31 Jan 2017 15:01:11 GMT
Connection: keep-alive
ETag: "5890a6b7-264"
Accept-Ranges: bytes

But I can't access the page because obviously LetsEncrypt is redirecting all http to https so I get referred back to the 301 error page!