We have officially confirmed from AWS that there is an issue. Below is the announcement we received from AWS.
===================================== Between 2:20 AM and 2:24 AM PDT, we experienced increased error rates for invokes to REST APIs in the ap-northeast-2 Region. The issue has been resolved and the service is operating normally.
Posted Sep 17, 2023 - 23:31 KST
Update
We suspect that the issue is related to an internal problem within AWS. A ticket has been created and we are currently waiting for a response from AWS.
Posted Sep 17, 2023 - 18:44 KST
Monitoring
The issue is being monitored and the service is now operating normally.