Hi @ML_2678909
Please note that the symbol_font detail option is applicable only to annotations that are owned by the object in which you have updated the detail option (drawing/model)
E.g. if you have a drawing with a shown dimension (owner is the model) then it would not be enough to update the symbol_font of the drawing, but also in the owner model of that dimension. Drawing owned annotations would use the symbol_font of the drawing...