Using v-for data as v-model value from object

I'm trying to add a default value to the radio button on page load. I'm looping over a json object by using v-for then trying to use the value in v-model of the radio group so that there would be a default value. For some the radio group doesn't take the v-for value. If I try to print out the current value in the v-for it works.

You'll notice that it prints out the value 3 above the radio buttons but the radio doesn't take that value 3 even though I tried to bind it with v-model