Phoenix socket origin

Hi,

I’m trying to deploy a phoenix application as described in deploy phoenix with releases but fail.

I have set the host in my prod config

config :miew, MiewWeb.Endpoint,
  url: [host: "172.xxx.yy.146", port: 80],

But the socket still fails with the following log:

22:24:19.061 [info] Running MiewWeb.Endpoint with cowboy 2.8.0 at :::4000 (http)
22:24:19.066 [info] Access MiewWeb.Endpoint at http://172.xxx.yy.146/
22:24:27.306 request_id=Fi5RQ0_JnM_25rUAAAAB [info] GET /sheet
22:24:27.330 request_id=Fi5RQ0_JnM_25rUAAAAB [info] Sent 200 in 23ms
22:24:27.638 [error] Could not check origin for Phoenix.Socket transport.

Origin of the request: http://172.xxx.yy.146:4000

Any help appreciated.

(xxx.yy are of cause numbers in the actual mix, log etc)