Did you ever get resolution? If not, I'd suggest trying two more things
1- change your DND settings to allow calls from "no one"
Test this in a variety of circumstances, with several numbers. If this works properly, then the problem is more isolated, and some of us can test the same "allow calls from: MyGroup" feature
2- if your phone worked properly when allowing calls from "no one", then the next thing to try is to completely delete the group tag "mi familia" then recreate it and add the people to it again. There might be something corrupted in the current mi familia data which could be triggering this bug. Since you'll do the group changes on your computer, you want to confirm that the group is seen as missing from the iphone before you re-add the group. Just to make sure that the deletion and re-adds properly came across from iCloud