OK, but your ZeroTier network (the one I can see on https://my.zerotier.com associated with your account) is not in the 192.168.4.0/24 address space, nor is it bridged into your LAN address space. It’s routed from the ZeroTier network to your 192.168.4.0/24 address space via the netgear router. Broadcast & multicast will not traverse router boundaries and that’s a tcp/ip bugfeature.