Video Indexer Transcript Update API Success Response Leads to Transcript Removal

I am encountering an issue with the Video Indexer API when attempting to upload an updated caption file after downloading and modifying it. Below are the detailed steps and observations:

Steps to Reproduce:

Download a caption file (e.g., .srt or .txt) using the below API endpoint.

https://api.videoindexer.ai/{location}/Accounts/{accountId}/Videos/{videoId}/Captions[?indexId][&format][&language][&includeAudioEffects][&includeSpeakers][&accessToken]

Modify the content of the caption file.

Upload the updated file back to Video Indexer using the below API.

https://api.videoindexer.ai/{location}/Accounts/{accountId}/Videos/{videoId}/Index/Transcript[?language][&setAsSourceLanguage][&callbackUrl][&sendSuccessEmail][&accessToken]

Observed Behavior:

The API response indicates a successful upload with message No Content

However, when I check the Video Indexer portal, the previous caption file is deleted, and the updated file is not visible.

Additionally, if I attempt to download the caption file again via the API, I receive an empty file.

Expected Behavior:

The updated caption file should replace the previous file or be visible on the portal.

The API should return the updated file content when downloaded again.

API Endpoint Used:

https://api.videoindexer.ai/{location}/Accounts/{accountId}/Videos/{videoId}/Index/Transcript[?language][&setAsSourceLanguage][&callbackUrl][&sendSuccessEmail][&accessToken]

Additional Context:

I am following the documented process for file upload and ensuring the file format is consistent with the expected specifications.

This issue significantly impacts our workflow, as it prevents us from reliably updating captions. Please investigate and let me know if additional details or logs are required to assist in debugging.

Thank you for your support!