Python UDP套接字；源停止时仍在接收数据；为什么？

import socket
import time

def udp_receiver(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.bind((host, port))
    print(f"Listening on {host}:{port}")

    while True:
        try:
            data, addr = sock.recvfrom(1024)
            print(f"Received message: {data} from {addr}")
            if data == b'TERMINATE':
                print("Terminating receiver...")
                break
        except socket.timeout:
            print("No data received in the last 5 seconds. Exiting...")
            break

    sock.close()

if __name__ == "__main__":
    host = '127.0.0.1'
    port = 12345
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.settimeout(5)  # Set a timeout for recvfrom
    udp_receiver(host, port)