This issue has come up with individual members before, often described as "broken word wrap" or "loss of margins". Often it just seems to solve itself after a bit.
Despite my recently-acquired high-falutin' title of "Global Moderator", which along with my wholly unearned status of "Grand Gearhead" and bright new "Blue Balls" makes my user blurb to the left come off like it might belong to Kim Jong-Un and Dennis Rodman's genetically-enhanced Love Child, I'm really just a glorified "Auxiliary Roach Stomper" for when the spammers come to town, and not a "Real Admin" at all. Still, I have a suggestion that might accelerate your browser's cure...
I believe that this issue might be caused by a bad browser "cookie" or conflicting multiple ones. A "cookie" is a little downloaded file that helps your browser remember various settings or preferences when you visit a site. This problem seems to occur most often shortly after either the browser or the computer's operating system has received an automatic update. I don't know which browser or type of computer or device you're using, but if you log out of this Forum, restart your computer, and then restart and log back in, that might force a new cookie download and cure this word wrap issue. If that doesn't work, you can search your particular browser's "Help" feature for guidance on "cookies" and, depending on the browser type, either delete them all or just those associated with this Forum or for a particular time period. This may prompt the site on your next login to send your browser a delicious fresh new cookie.
By way of diagnosis, if you log out of the Forum and suddenly the messages appear again with normal word wrapping and margins, then a bad or corrupted cookie is likely the culprit.
Good luck, and please keep us posted here.