Your last 5 files were empty (0 bytes) - times starting with 11-05-05, 11-06-34, 11-08-43, 11-12-18, and 11-40-07.
The one before that (starting with 10-55-28) had a leading @ before the json.
I believe your problem for the earlier file (starting with 10-43-25) is that you’re passing in the twitch ID and not the established game user ID (whatever was set for identifier from https://dev.twitch.tv/docs/v5/reference/users/#create-user-connection-to-viewer-heartbeat-service-vhs - it looks like you’re using the Twitch user name?)