Try spritzing the chips with water to see if that "wakes it up." I'd be curious about that. The fungi still have their "food" (i.e., the bark) and they're hard to kill, so the only other variables I can think of are water and maybe temperature. And maybe the disturbance of cutting into the bark.
I know that those little one-celled critters (noctilucent miliaris?), that create the phosphorescence in ships' wakes, glow when disturbed. I did a little research on those critters a long time ago (ca 1963) when there was an "invasion" of them into Long Island Sound. Quite interesting, especially watching the waves glow. I collected a mess of them by sieving them with my ex-wife's scarf and put them in a big fishbowl. Fun to watch the whole bowl light up when you tapped it.
Terry, 230RN