I think the only practical test for sentience is 'can you argue convincingly you should be accorded human rights'? I still expect an AI to be the first nonhuman to pass it, but that shouldn't obscure the fact that many nonhuman beings are incredibly intelligent.
Coordination and functioning as a network is conceptually not related to sentience; one could argue that it's necessary, but it's not sufficient and perhaps even an orthogonal issue.
It seems like a broad group of fungi species are able to function as a network for its basic function of self propagating
And that a smaller group of fungi species are able to self propagate with complex functions while disconnected from the network
Feels very misunderstood, to me