Sounds like the actuator linkage may have come off. Hands-on inspection needed.If you don't work on your car then use this link to find a good shop near you.
https://repairpal.com/repair-shops
Alex
RepairPal Certified shops can diagnose and repair your 2003 Buick Park Avenue. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Thanks. How do I open trunk to see and reattach linkage?