Did you explore Timber Hearth a bit more? There may be something there that helps give a clue for what's going on in Dark Bramble. Someone in the village might have mentioned it as well.Keeps saying go to sunless City and can't find anything. On dark bramble I went into the nest and couldn't find anything. On deep I can't get believe current. On the hanging city I moved the forge but the elevators were broken and I was stuck.
Don't be afraid to use the scout as a proxy for yourself as well to see what is and isn't possible, or just to see where it ends up.
Anyway, sometimes the answer (or even the solution itself) is on another planet entirely. I would say trying to brute force them will only need to frustration, so I'd try to investigate new places or planets. (Chatting with members of the expedition, each playing an instrument you can track, is usually a good way to get new clues or points of interest.)