Agreed. If it takes a week to make a line change it'd be very unusual IMHO if the entire team were not aware by that point of some the challenges involved. It may even warrant a short presentation on the technical challenges and how the issue was tracked down or solved; good learning opportunity.
On the other hand, if somebody is constantly disappearing for a week+ with a low complexity ticket, gives cagey standup updates, and then submits a PR that looks like it was thrown together in an hour.. That's a red flag that needs attention.
If the engineer can't convey why it took a week to find that one-line, they should work on their communication skills. A good manager can help set expectations for an engineer who has underdeveloped soft skills.
I just spent a week and a half tracking down a bizarre issue in a 3rd party library and filed a fix for it. It was simultaneously frustrating and fascinating, but I never once was worried that the team didn't support my effort because I kept the team in the loop during daily standups. I've also been lucky to have excellent managers who believe in letting the engineers work.