Formatting removed when posting

[Staccato]

This has probably been answered elsewhere, but I can't find the ticket so forgive me if this something you've already dealt with. I can't edit any of my posts and all formatting (including line breaks inbetween paragraphs) is removed when I post, resulting in a single block of text. I think this problem has happened in the past, and it's typically sorted in a few days, but it's been about a week now and it's still there. Any advice?