Nostalrius Begins - Quality wow vanilla realm (1.12)

I'm having a lot of trouble with the general chat. While I have no problems with whispers and such, half of the time my posts aren't displayed in the general chat.
I googled and found many tips: leave and rejoin the general, relog, flat-out exit the game etc, anything I do the general chat works again for the grand total of three, maybe four texts before it bugs out again. Sometimes it doesn't work at all and I have to log out more times consecutively. I heard any of those should fix the problem without flaws, but that doesn't seem to be the case, so maybe I need to change some config files or something?

I'm below level 15, but seeing how I'm not using any addons, and the chat doesn't let me post anything even the first time I use it, I'm worried it's not the spam filter

You should avoid using public chats until you are lvl 15 as you can very easy get auto-banned by mistake.

If I was you I would wait and see what happens at lvl 15.