The font in one or more of your Reference Notes callouts is overlapping or spilling outside the callout box.
This issue typically only results from a problem defining the font used for the attribute value.
You can check in the AutoCAD Text Styles dialog box to see which font the Callout Title is set to. In all likelihood, it's set to a font that is not installed, and there is a substitution for the Stylus BT.
You can also go to the General Preferences screen, select the Callout Title font, and Edit it. Select a font you would like to use for the RefNote callouts. You can test this font assignment by selecting the Fonts option in the F/X Site menu, and inserting some Callout Title text into the drawing.
For information on RefNote callouts, see our Reference Notes Callouts documentation.