Presuming that INS+NumPad 3 used to invoke the MS-Word Word Count dialog, you could just use the Word shortcut ALT+R,W.
If it didn't, I can't be of much help. I know that sometimes JAWS does its own custom thing through scripting that makes information more easily accessible, and if that's the case you were probably not getting the MS-Word Word Count dialog. But they also have had the habit, on occasion, of introducing a JAWS shortcut that is just an alternate way of invoking a native shortcut, and I hate that because it's generally unnecessary and the JAWS shortcut often saves zero, or sometimes one, keystroke over the native program command.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
One does not discover new lands without consenting to lose sight of the shore for a very long time.
~ André Gide