I think where people get caught up is that there’s a lot of confusion on definitions (partly since consciousness is almost certainly a spectrum). But a lot of people confuse human sapience with a requirement of consciousness which is not really the case. When looked at in that light, conscious fungus makes a lot more intuitive sense.

My favorite description of the difference was from the cognitive scientist Daniel Dennett. He gave the example of a dog sitting in the sun. When we see our dog sitting in the sunshine looking content, it is almost certainly enjoying the warmth, and we are probably correct in assuming the dog is feeling content in a way that we can relate to. The difference with a human, is that we can reflect on that state; we can contemplate the experience itself (sapience) rather than just sensing it (sentience).

So complex mycelial networks probably allow some level of sentience (experience states of sense, awareness of the environment), but we shouldn’t think of it as something that is contemplating it’s existence on a higher level. Would we define that as consciousness? Perhaps the difficulty of that assessment is just in applying a single word to represent reality.