If you switch from overriding the text preferences in a project to using the global settings or vice versa, specific conditions can make the older font (family and size) linger.
Set the project preferences to override text formatting for the project, and set a different font from the main preferences
Create a new document (A) in the project; it should use the project-specific preferences
Deselect overriding main text formatting
With the cursor at the end of the document A’s text, choose Documents>Convert>Formatting to Default Text Style (with no formatting preserved); it should convert to the main preferences
Type at the end of the document (from where the cursor is)–the new text remains in the project-specific font.
This only seems to happen with the font; line spacing and indents don’t persist. It also only happens if the cursor is at the end of the text when the conversion happens and it will happen repeatedly–if after step 5 you again run the conversion while the cursor remains at the end of the doc, typing will continue in the wrong font. If you switch documents after the conversion and before typing, then return, the conversion will stick.
This can be done also going the other direction–set the project to override text preferences, then convert a document while the cursor is at the end of the text. New typing will use the old font.
I’ve seen this happen under other conditions as well (but it was a bit ago when it happened so I don’t remember them precisely), when using conversion in an empty document. It seems this tool doesn’t quite work right if there is nothing to style yet, in general, and isn’t tied specifically to external conditions. Just so long as there was styling in the document that did not match the default.
Ah, in fact this happens with the paragraph indent when your cursor is at the beginning of an empty line. I just switched from my global default of first-line indent to a project override of no indent, with my cursor at the top of the document, beginning of an empty line. It initially seems to convert, the cursor jumps to the left (so no indent) but as soon as I type, it indents. The same occurs if the cursor is on an indented empty line elsewhere in the document–the document style conversion won’t stick for the line.
The conversion only operates on the text. It sounds as though the typing attributes are just lingering, which are set entirely separately. As minor as it is, this might be tough to fix, because of the separation between the views and the underlying model data that is affected by this action, and the action’s lack-of-knowledge of which views should have their typing attributes updated. Added to the low-priority list, though.