A durable power of attorney will expire upon the principal’s death. A non-durable power of attorney will either expire after a certain period of time or when a certain event occurs, depending on how the document was drafted.
Regardless of the type of power of attorney you have, the agent’s authority will always end if you die. Continuing to act on behalf of the principal after they’ve died is illegal, which may result in criminal charges such as embezzlement, fraud, or theft.