无法接收其他设备UDP组播消息的问题排查求助

我在Windows 10本机上运行两套UDP组播收发脚本（分别用C语言和Python3实现），其中Python3版本的脚本如下：

sender.py #

import socket
MCAST_GRP = '239.1.1.1'
MCAST_PORT = 1234
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)
print("Sending")
sock.sendto(bytearray("str()", "utf-8"), (MCAST_GRP, MCAST_PORT))
data, address = sock.recvfrom(1024)
print('received %s bytes from %s' % (len(data), address))
print(data)

receiver.py #

import socket
import struct
import sys
multicast_group = '239.1.1.1'
server_address = ('', 1234)
# Create the socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
# Bind to the server address
sock.bind(server_address)
# Tell the operating system to add the socket to the multicast group
# on all interfaces.
group = socket.inet_aton(multicast_group)
mreq = struct.pack('4sL', group, socket.INADDR_ANY)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
# Receive/respond loop
while True:
    print('\nwaiting to receive message')
    data, address = sock.recvfrom(1024)
    print('received %s bytes from %s' % (len(data), address))
    print(data)
    print('sending acknowledgement to', address)
    sock.sendto(bytearray("ack", "utf-8"), address)

现在遇到的问题是：这台Windows 10机器连接了一台未知系统的物理设备，我无法通过上述脚本接收该设备发来的组播消息，但Wireshark可以捕获到该设备通过eth0接口发送到239.1.1.1:1234的组播消息。我发现脚本生成的流量走的是VirtualBox Host-Only Network接口，我没对这个接口做过相关配置，不确定是不是因为这个导致无法接收外部设备的UDP组播消息。

另外我在最新版Kali Linux机器上也做了相同测试，同样无法接收该外部设备的组播消息。

补充信息：我给Windows 10的物理网口eth0分配了IP地址192.168.1.100，可以通过指定软件使用该接口与外部设备传输以太网、TCP及IPv4数据包。本地脚本运行时的收发示例输出如下：

sender输出 #

Sending
received 3 bytes from ('192.168.56.1', 3000)
b'ack'
Process finished with exit code 0

receiver输出 #

waiting to receive message
received 5 bytes from ('192.168.56.1', 55132)
b'robot'
sending acknowledgement to ('192.168.56.1', 55132)
waiting to receive message

如果有需要补充的信息，请告诉我。

内容的提问来源于stack exchange，提问作者JRsz