Every now and then and becoming more frequent when I click on a topic instead of going to the topic I jump to the top level of the forum. it is becoming very frustrating having to do everything 2 or 3 times.
I have seen that a few times today as well. Thought that it had been fixed recently. Perhaps not fully yet.
I'm on a Win10PC, how about you?
This is an issue Arduino are currently working on.
Yes it is a royal pain in the buttocks but unfortunately apart from pointing upstairs to this topic there is nothing I can help with.
Only about 20 times today for me LOL so better than most days.
Even it's happening to me. Just reporting.
CrossRoads:
I'm on a Win10PC
Same.. 
Hope Arduino can fix it soon. 
I am on Win7 Enterprise and also Linux so it is not operating system related.
And only 20 times???? Lucky you.
It's a pain; also happens on Android/Chrome. Luckily you can go back on Android/Chrome without loosing your message.
Lesson: Compose your message in an editor, copy and paste in the forum (it has been said before). But it should not be necessary.
I'm quite sure this relates to the fact that the forum sometimes does not realise that you're logged in (e.g. one does not see 'unread messages' and 'updated topics') when getting to the forum or being on the forum. So when you post, it thinks that you're not logged in and takes you to the home page.
It affects multiple OS's BTW so that does not really have any bearing on the matter and neither does the browser being used.
The overall issue seems to have been a deployment of some extra software that Arduino does not have much control over at this point in time.
Please don't go off saying remove it etc etc as that cannot happen !
They are trying hard to mitigate the issue but thats all I know.
ballscrewbob:
They are trying hard to mitigate the issue but thats all I know.
Well what we can do is encourage their effort