The packets can be rejected due to the MAC address mismatch between the remote device and address of your ethernet adapter. Apart from this, write a simple UDP multicast receiver in another programming language (such as Python) or use a network utility tool to test whether the system can receive multicast packets outside of MATLAB. This can help determine if the issue is specific to MATLAB or the system itself.
Also, check if your firewall settings are allowing incoming UDP packets on the port you're listening to. Firewalls can block incoming traffic, which would prevent MATLAB from receiving the packets.
For further information, refer to the documentation link below:
