found the issue, tried 391 driver and got SMI to work properly. Going to try updating from that driver see what happens.

Edit: updated driver and back to same old thing. WDDM not working. Assuming somethings going on with newer Nvidia drivers. Going to try older 400 series driver next see what happens.

Edit #2: Seems 399 is working for SMI. for P104-100 I haven't seen any difference in wattage using Inspector vs MSIafterburner. at best 3 watts maybe?