For me, mobile mode seems to be here to stay.
Luckily, my computer has both Internet Explorer and Mozilla Firefox, so I can just use the Firefox program to see the normal screen. However, it would be nice for this one, Explorer, to be fixed as this one is quicker to load.
I don't know how or why it happened, but I logged out thinking it might let me go back to the standard screen (it did). When I logged back in it displayed a message that it was logging in and to click the link if not redirected in so many seconds, I just let it sit there and then a screen popped up saying there was an error (maybe I waited too long?) and before I knew it I was back on the normal screen! I very quickly went into the settings and changed it back (it still said it was set for mobile, I selected the Encyclopedia-Titanic mode).
Not sure how it worked but it may have something to do with the broswer blocking redirects. Might do the same thing again. Just a thought.
I hope someone can fix it though, since it appears that the link for the normal forum button you tried (and myself as well) is non responsive with a bad link. Perhaps the administrator could repair the button? You might need to send a message as I don't know if anyone has seen this post yet?
Just an update, whilst viewing the community on a mobile device (which defaults to the 'Mobile' version) I attempted to select the 'Full' version using the button. It did not work. So this is still a concern should someone get stuck in the 'Mobile' version.