Problem with formatting excerpt in blogs and events

In the last 2 days or so, I've started having trouble editing the Excerpt box in the Options tab of blog posts and events. It won't let me select any text other than something at the top of the box, and even with that I can only double-click and select an entire paragraph and not individual words. I can use the arrow keys to move my cursor through the text, but I cannot select individual words. For example, I wanted to italicize the title of a book, but I couldn't select the title. Instead, I had to use the arrow keys to move the cursor down to the text in question, use the keyboard shortcut for italics, and retype the title. Also, the text block toolbar has changed in the Excerpt box. It doesn't have the standard options it used to have, and even the Format dropdown menu has changed. I've included a couple screen shots to illustrate the problem with the toolbar. Is anyone else having a problem editing the Excerpt of a post or event? I'm using the Impact template (I mistakenly said Brine earlier). I checked my other websites (the ones that use the Brine template), and I'm having the same issue. So it appears to be independent of the template. I'm thinking this is a bug and hopefully not a "feature."