Has port forwarding been stopped?

I have been using port 32400 for a while, but it stopped recently. On the support chat I was told that it was not allowed to forward because of hackers(?) and referred to the web page. 32400 is not listed and they could not tell me what I could use. After being on with them, now I can no longer even log on to my router (Cox Panorama). I have never gone over my limits, so have no idea what that was about.