Your browser will (should) wrap the text to fit inside your browser window.
However, if someone (rudely) includes a super-wide picture or a long link containing no spaces, the browser cannot wrap, and instead increases the width of the column.
This is often the cause of the symptom you cite.
It should pass when the offending post falls off the first page.
It’s aLL the posts for me.
So, I should wait an hour or so and see if it returns to normal?