TextEdit disables menu when selected text has different fonts/styles

Prior to Sonoma, when using TextEdit (virtually always editing rich text docs), I could select any text and add/remove a style to whatever styles were present in the text. For example, if I had a sentence: This is an example of **bold**, and I wanted to use *italics* for the whole sentence, I simply selected the whole sentence and clicked the *I* button. Simple, and common to most editors. In Sonoma, however, if I select the wole sentence, the menu options become gray/disabled. I am forced to first select the non-bold part, italicize it, then select the bold part, and italicize that. Since I edit docs extensively, this requires a LOT of extra time. I've searched haven't found anyone else mentioning this change, so I'm wondering if it is specific to my machine? Or some setting I'm missing? Thanks in advance for any suggestions.