Thanks for using Bitnami. We have a Support Tool that will gather relevant information for us to analyze your configuration and logs. Could you please execute it on the machine where the stack is running by following the steps described in the guide below?
Please note that you need to paste the code ID that is shown at the end.
Additionally, O think your question is more related to the Open edX program than to the Bitnami installation (notice we only configure open source programs from upstream). Can you open a new question in their official forums for further help on this? Maybe this requires any additional configuration in their latest Koa release.