Trouble with inbound multicast on home network

I am using UDP multicast to send messages to an embedded host (Raspberry Pi) in my home network but I am running into issues receiving multicast traffic on Ventura 13.4.

I have a simple Python receiver/sender script:

receiver.py (with from_nic_ip set as the local address related to the port that I want to bind to, multicast addr: 224.0.0.0, multicast port: 42073)

def receive_loop(from_nic_ip, multicast_group_ip, multicast_port):
    receiver = socket.socket(family=socket.AF_INET, type=socket.SOCK_DGRAM,\
            proto=socket.IPPROTO_UDP, fileno=None)
    multicast_group = (multicast_group_ip, multicast_port)
    receiver.bind(multicast_group)

    if from_nic_ip == '0.0.0.0':
        mreq = struct.pack("=4sl", socket.inet_aton(multicast_group_ip), socket.INADDR_ANY)
    else:
        mreq = struct.pack("=4s4s",\
                socket.inet_aton(multicast_group_ip), socket.inet_aton(from_nic_ip))
    receiver.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)

    while True:
        buf, _ = receiver.recvfrom(BUFSIZE)
        msg = buf.decode()
        print(msg)

    reciver.close()

sender.py

def send_loop(host_ip_addr, multicast_group_ip, multicast_port):
    sender = socket.socket(family=socket.AF_INET, type=socket.SOCK_DGRAM,\
            proto=socket.IPPROTO_UDP, fileno=None)

    multicast_group = (multicast_group_ip, multicast_port)

    sender.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 1)

    sender.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF,\
            socket.inet_aton(host_ip_addr))

    while True:
        print("Sending data!")
        sender.sendto("test".encode(), multicast_group)
        time.sleep(1)

    sender.close()

If I run macOS as a sender and the Raspberry Pi as the receiver, I get the expected output: "test" printed continuously. If I reverse the roles, I see no "test" output.

I have verified that the script works as a sender/receiver by duplicating the test on a Linux desktop and I see that the two nodes can communicate with each other as both a sender or receiver.