As Stefan suggested, the issue is probably with your external ports, which don't affect internal network traffic.
If you have a firewall restricting incoming traffic to the network you will have to open the ports on this device/computer, probably via a web interface.
I'm not an expert, but have had to learn a bit about this, so I hope this is helpful if not incredibly clear!
Kenny
V25 & 26 (fully patched); Mac Ventura, MacBook Pro M1 Max