500 Error upon GitLab Login

Recently I’ve setup a GitLab VM (using Ubuntu 18.04 LTS OS), reverse proxying through an Nginx VM. Both VMs (along with others) are hosted in Proxmox VE 5.3 on my R710 Server.

Tonight I got it so the GitLab Login screen comes up when reverse proxying through Nginx with a proper DNS URL (http://git.myreserveddns.com). After logging in, I receive 500 Whoops, something went wrong on our end. After logging in, if I go to http://git.myreserveddns.com/admin, or any other valid GitLab URL, the proper GitLab page comes up. If I go back to http://git.myreserveddns.com/ while still logged in, I receive the 500 error. Any idea what’s going on?

Let me share the following files …

Nginx VM: /etc/nginx/sites-available/git.conf

server {
# The IP that you forwarded in your router (nginx proxy)
  listen; listen [::]:80; # Nginx's Internal IP

# Make site accessible from http://localhost/
 server_name git.myreserveddns.com;

# The internal IP of the VM that hosts your Apache config
 set $upstream; # GitLab's Internal IP

 location / {

 proxy_pass_header Authorization;
 proxy_pass http://$upstream;
 proxy_set_header Host $http_host;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 proxy_http_version 1.1;
 proxy_set_header Connection "";
 proxy_buffering off;
 client_max_body_size 0;
 proxy_read_timeout 36000s;
 proxy_redirect off;


GitLab VM: /etc/gitlab/gitlab.rb (vast majority of the file is commented out, so I’ll just share the uncommented bits):

external_url 'http://git.myreserveddns.com/'
nginx['redirect_http_to_https'] = true
registry_nginx['redirect_http_to_https'] = true
mattermost_nginx['redirect_http_to_https'] = true

Anything else I should post? Any idea what could be causing the issue?

NOTE: SSL is not set up yet, and I have no intention to until I solve this issue.

So … this is odd.

Restarted my Server today, and when I login, I am no longer getting the 500 error. I haven’t updated the server or anything. Thoroughly confused. I guess I’ll report if I run into the issue again here.