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.
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'
Two branches
沒被指出來的事
最貼近核心畫面的一支：東西在，手沒有伸出去。這裡沒被指出來的是一個狀況或一種情緒。
adjective · C1
Really there, but not noticed, not spoken about, and not dealt with. It is used about feelings, problems, or facts that everyone passes over in silence, sometimes without meaning to.
沒被正視的
該說出口卻沒說的承認
同一個缺口，但這裡少掉的那句話是「欠人家的」：不是沒注意到，而是該給的交代沒給。指出來的動作在這裡變成道謝、署名，或一個正式的職稱。
adjective · C1
Not given the public thanks, praise, credit, or reward that it deserves. It is used about work, help, or a contribution that other people benefit from without ever saying where it came from.
沒得到應有肯定的