While Koboh is filled with rumors in Star Wars Jedi: Survivor, there is only one rumor that you can find in Shattered Moon, and that is also quite easy to miss if you don't know what you are looking for.
If you have not unlocked Shattered Moon yet, you need to first reunite with Cal's crewmates at Jedha, after which you will get the objective to explore further to learn more about Tanalorr. The first stop is Shattered Moon, and after taking down the Magnaguard boss, players will come across a Maintenace Droid, which might look quite innocuous but will help you get the only rumor in the area.
Find The Location
After you have spoken with the Maintenance Droid, you will get the rumor added to your rumors tab. If you can't find the location of the Maintenance Droid, you can refer to the map above to pinpoint the exact location where you need to head to. Once that's done, track the rumor to get the exact location where you need to head to. The Maintenace Droid mentions that players need to head to the lower levels of the factory and investigate the area. While the area is not that far, you need to be careful while treading the path as it is filled with traps, making your short journey quite eventful.
To start off, right after talking to the Maintenance Droid, take a left and take the staircase to proceed forward. Take a right, and you will notice a climbable wall with electricity running on it. There are two adjacent walls, and you need to switch between them to avoid the electricity. You might also need to wait in between to avoid the electricity in the gaps. Once you reach the top, you can need to use the beam above to reach the other side.
Go Ziplining
Take a right, and you will notice another beam running on top of you, but this time it has electricity running across it as well. This time, you need to use the extensions of the beam on either side to avoid electricity. You will land on a platform with a zipline in front of it. Once again, you need to switch between the ziplines to avoid the electricity. You will then come across a set of walls opposite each other, which you need to wall-run on. Once you see a zipline, jump on it and then immediately drop.
Head inside the area with a large orange grill and hook to the platform above. You will find another maintenance droid here, and you can speak to them before heading to the next section. Use the zipline right in front of it and then follow the path after landing on the platform. At the end of the path, you will find a chest with the Stem Canister, which you can collect to complete the quest.