Welcome to the weird and wonderful world of Vanilla 2.8 (report problems here)
Big changes afoot! I've updated the forum to the new shiny Vanilla 2.8 featuring new and (presumably) improved rich text editing (Huzzah! Emoji! 🎉), and a new fully responsive theme (no more limited Mobile theme required).
But nobody's perfect, so let me know if anything's amiss. We'll tweak as we go.