Vmc tungsten fly is a killer but For me the fish wouldn’t touch it if I didn’t make sure my knot was pulled to the bottom of the eye hole. By doing this it makes the jig sit horizontal and I tipped mine with wigglers or waxies.
I was using one today and forgot my plastics in the truck so I started using them plain. And I caught a couple fish like that before I tipped it with a spike. That ice fly is a really versatile bait, I had to do the same thing David said and make sure the knot was letting it stay horizontal, when it was vertical I couldn’t get the same commitment out of the fish.