What you think is a Dynamic block may and probably is subjective opinion... You may be right, but also wrong... I offered free revision that in general satisfies your request... If you think you are right and adress this as a bug in AutoCAD, then you should adress AutoDesk - not me... And as they are bussy and probably don't want to fix all bugs related to products they released, they may charge you extra to satisfy your specific needs. I thnik that my reply was fairly correct and if you wish you can carry on to try fix on your own... I'd in that manner suggest you to write down additional sub function (IsDynamic-p) and inside it check for any parameter you think is related to Dynamic blocks and if there exist even single, you adress return of sub as T... Then in main routine you should replace this line (= (vla-get-IsDynamicBlock obj) :vlax-false) with (not (IsDynamic-p obj)) and I suppose that now this time it should work as expected... If you wish and find appropriate you can post your discovery at this topic and maybe someone that has the same issue in the future may benefit from your findings and your generosity.