Apologies for any inconvenience this may have caused, but we were made aware of a Builder legacy issue. That issue is now resolved. If you are still experiencing the problem, try the following:
1) Restart State of Decay 2;
2) Demote your Builder leader;
3) Promote another leader;
4) Complete "A New Beginning" for that leader;
5) Take your Builder out to grind standing (influence) until they are a Hero again;
6) Demote current leader;
7) Promote the Builder.
Alternatively, you can switch maps after relaunching the game. However, this will mean you have to defeat all plague hearts again.
Please submit a tech support ticket if you are still having issues.