don't forget trailing slashes!

nginx-ssl/nginx-ssl.conf

@@ -34,10 +34,10 @@ http {
         include /etc/letsencrypt/options-ssl-nginx.conf;
         ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
 
-        location /brave {
+        location /brave/ {
             auth_basic "Are you Brave enough?";
             auth_basic_user_file /etc/nginx/htpasswd;
-            proxy_pass http://dock.lag:5000;
+            proxy_pass http://dock.lag:5000/;
         }
 
         location / {