No 'New Topic' on Firefox

I logged in on Firefox and quite desperately looked for a way to open a net topic. I found none. Then I logged in via Chromium, and there it was. This is where I write this topic now.

So: On Firefox there is no button to create a New Topic!
On Chromium, on the very same computer, there is one!

Using Linux Mint 21.2

I am on the latest Firefox 125.0.3 on Windows 10 and it does show though…

Hmmm, very odd. I rebooted and now the 'New Topic" button is present???