I need help, In the "Metrics" display you can see, for example, that the node "A" is not connected to any of the other nodes. In the nodes overview, however, it says "Healthy" and if I want to reconnect to the network on the server via "netclient connect -n name" the display shows that the connection already exists. What can you do to make it work again? And why can some nodes not connect to some Nodes but are connect to others?

make sure ICMP (ping) is enabled. Metrics relies on ICMP, so if it is disabled by firewall, it will show this way even if it's healthy.