I have a shohin trident that is apparently half dead as all the top growth died back, and to compound the matter there is now a white and orange fungus growing on and around the trunk on the side that died.
There is still one live shoot on the other side and I'm going to continue nursing it, but all I can do at this point is wait.
I see you are from Detroit. I'd bet your death/dying is from exposure to cold during overwintering causing root damage then root rot. The 'fungus' you see I DOUBT was the killer but an after effect. Store tridents in a styrofoam container w/ holes in bottom and back filled w/ mulck above pot, unless you can safely control your temps.
Then there's my Seiju elm that isn't showing signs of waking up yet. The buds are there, the cambium is still a vibrant green, but nothing's happening and I feel like it should be by now.
Again, a touchy overwintering tree imilar to tridents. perhaps too cold of storage.
My JBP has sawfly larvae munching away at the needles. I've manually removed all that I can see and blasted with water and they still return. Finally last night I sprayed the whole tree with neem oil. Hopefully that helps.
You may find the sawfly cats returning because you just 'blew them off'. You need to kill them which is very easy w/ any spray labeled for cats. Just get a small spritzer bottle if they only infect your bonsai. If yard 2-needle pines you might need a sprayer. They can ruin a mugho and others real quick!
Dale