We tried to get work log from Jira API. However, we found that certain work log throw wrong author name as the it's username.I found that in the app_user table, the user's user_key is the same as the author name so I changed that to be the same as current username.
However, it still doesn't update in the work log.
So the app_user.user_key field will match the username in JIRA when the account is first created in JIRA. But if that account has ever been renamed in JIRA, then the cwd_user table gets updated with the new values (along with the app_user.lower_user_name value) while the app_user.user_key field is expected to remain the same in JIRA, forever.
If you modified that field directly via SQL then I fear you might have messed with the way JIRA is storing that historical information such as worklogs and issue edit history.
But back to the worklog problem, I think you are seeing a known bug in JIRA JRASERVER-36642
The good news is that there is a workaround for this on that bug ticket:
Use the /rest/api/2/user endpoint to retrieve the user's username based on its key. This should return something like:
"displayName": "Matheus Fernandes",
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