Thanks for the advice everyone. But I think I didn't communicate the problem that well.
I run open-world sandbox games. So dropping rumors/hooks/jobs into the PCs' laps and letting them pick isn't the problem. Getting them to pick one also isn't really the problem. It's what comes next.
The players take up the rumor/hook/job and ask a few initial questions, I provide the answers, point them clearly to some next possible steps, then they largely seem to just falter and stop dead. The fact that they have options seems to confuse them. That there isn't one blinking neon sign pointing to an obvious right choice puts them into analysis paralysis. They're looking for the rails when there aren't any, and the fact that they can't find them causes them to freeze.
I had one group talk themselves into a dead end they'd decided was the only possible option and when I communicated to them that nothing was happening in the location, instead of rethinking or adjusting at all, they literally just sat down and waited for the plot to come to them. At a later point the same group decided they wanted to talk to an NPC. When I told them the NPC was out of town and wouldn't be back for a day or two, they decided to just hold up in the inn where he was staying and waited. Legit refused to do anything else both times. There were other hooks, other rumors, other NPCs or locations they could visit or investigate, other angles they could check out for the same rumor/hook/job...but they noped out.
Now, while I recognize the "hurry up and wait" group is uniquely bad, a lot of other groups I've run for still get caught up in the analysis paralysis I talk about in the third paragraph. I'm a fan of the Alexandrian blog, so I pepper redundant clues throughout, with multiple clues pointing to the same conclusion. I've also run CoC for decades, so the mystery element isn't a problem. I know better than to lock things behind one roll or check. I know better than to use red herrings. I don't devise overly complicated stuff. I love Return of the Lazy Dungeon Master, so I'm fine with moving clues to wherever the PCs are. I'm also far more of an improv referee so I have no problem just following the PCs wherever they go.
The trouble is, after a few choices...they just freeze. They're looking for the tracks and the fact that they can't find them stops them dead. I've been running and playing RPGs almost 40 years now and, in my experience, this is a uniquely 5E player thing. I've never had this issue with any other game or any other edition of D&D. It literally never happened until running 5E.