Luckily, the forum is almost always available for me, except in rare cases.
My entire Lazarus development OS is in a virtual machine. When I'm finished working with it, I don't shut it down, but simply save its state to disk. It's like hibernation for a real machine. This way, my browser stays open for months, and I never log out.
Although sometimes I close and restart the browser, and the forum/wiki still works. Basically, it's probably because my cookies are never cleared.
But in incognito mode, I can reproduce the same login issue.