Based on the default package (this support forum) I can use the redactor box to create a reply.
Step one, click on bold, start typing = created text in bold, bold button stays highlighted
Step two, click on italics, keep typing = created text in bold italics, both buttons stay highlighted
Step three, click on underline, keep typing = created text in underlined bold italics, all buttons stay highlighted
Step four, click on strike through, keep typing = created text in struck through underlined bold italics, all buttons highlighted.
Step five, backspace the cursor, each button turns off as the text style disappears.
This works OK.
In my style, when I do exactly the same thing, the button highlights disappear as soon as text is created. No clicking is done in the text area so there should be no "loss of focus". I have gone back into EXTRA and removed any CSS related to the redactor box. There is no styling done via the Rich Text Editor section in Styling Properties. As far as I can see there is nothing set that would have any bearing on the redactor box, but I still get the button highlight problem. Has anyone else run into this situation?