@bai can you confirm that you are not hiting any of the API Limits?
https://learn.microsoft.com/en-us/rest/api/time-series-insights/reference-api-limits
See also the Best practices for planning and preparation: https://learn.microsoft.com/en-us/azure/time-series-insights/how-to-plan-your-environment#best-practices-for-planning-and-preparation
Thanks