Hello Nuno,
I am sorry for the late reply.
May I know, do you use Joomla 3.3? If yes, it most probably because Joomla 3.3 have change some settings and EasyDiscuss need a simple fix for this. This is a known issue for EasyDiscuss with Joomla 3.3 and it is already fixed in the latest version of EasyDiscuss. Can you update EasyDiscuss to the latest version and see if this issue has resolved. If you have done any customization to EasyDiscuss, it is advisable to do backup before upgrade because EasyDiscuss will override the existing code to the latest. If this is not the issue, perhaps you can provide us appropriate screenshot?
Regarding this, "Joomla articles start displaying in frontpage layout discussions like if they were a discussion." I'm not sure if I understand you well. Perhaps you can provide us with appropriate screenshot so that we will have a better look of your issue.
If you can upload to a temporary online site for us to debug and investigate this issue is most welcome because we can assist you much quicker.
Please be advise.
Thanks.