You can think of it like this: something real is sitting in plain view — a problem, a piece of work someone did, a person everybody actually listens to — and nobody points at it and says so out loud. The thing does not change. What is missing is the pointing and the saying. That gap is the whole word, and the three uses are just three different things left unpointed-at: a problem, a contribution, a role.
可以想成：有一樣東西明明就在那裡，但沒有人伸手指著它、把它講出來。東西本身沒有變。少掉的是那個「指出來、說出口」的動作。這個字每一個用法都是這個缺口，差別只在沒被指出來的是什麼：一個問題、一份功勞，還是一個角色。
From the word’s history
un- + acknowledged, where acknowledge is to nod and say that something is so; the un- removes the nod, not the thing.
un-（不）加上 acknowledged（被承認）。acknowledge 是「點頭承認有這回事」，un- 拿掉的是那個點頭，不是那件事本身。
packet evidence: Wiktionary etymology tree for unacknowledged (kaikki:3f6f69a190036ae4), 'From un- + acknowledged'
登入就可以看每一支怎麼連回核心畫面。