Hi all.
To reiterate some of what Nick Darnell said above:
If you have additional information about a bug report, please click on the “Answerhub” button on the report to go to the original community report. You can contribute there. If one doesn’t exist, you can create a new Answerhub bug report and reference the ticket. Please be aware we are only looking for useful information to work towards its resolution. If you are a programmer and can fix the issue yourself, please submit a Pull Request to Github. 
Sometimes bugs can have multiple different ways to reproduce it. A bug report only needs to list one successful method, and once the root issue is addressed it should be fixed for all reproductions.
Sometimes issues get fixed without knowing the specific changelist which resolved it. These may be marked as fixed without additional information.
I have updated UE-6451 with a developer note to clarify why it is marked as Cannot Reproduce.
Cheers