Can't get hosted push server working

Hey

Which version of Mattermost or GitLab are you using?

8.5.1

A link to documentation you're using to install and the specific step at which you're failing

As stated in the documentation, I added the http://push-test.mattermost.com but for some reason none of my team members receive any push notifications ever.

What variations have you made that differ from the instructions?

Actually nothing.

Relevant output of error logs in mattermost.log

http://paste.frd.mn/cimir

Thanks for any input!