Code Showing in Posts in Backend

P tags and br tags are appearing throughout our blog posts in the backend even though they were previously invisible (for many weeks, until a few days ago). It’s as if we were in a Word document and hit “show formatting” and now code is appearing everywhere. The presence of the code is not harming anything about how the posts display but it does make it harder to work within the posts on the back-end.

Does anyone know how to turn this off?