OK, so I tried to run Zap using Nginx as web server. As a result, I'm getting a few unintelligible error messages in Nginx logs (at least for me) and some unexpected behaviours. I'm switching back to Apache, see if it works any better. And if it does... well, it will confirm I need to solve a few things with my Nginx based configuration.
This message is actually a test, as it will help me check if my public messages do appear in the public stream when using Apache as a web server. Let's figure this out.