Based on our investigation, there were two aspects in this incident
For point 1, we verified all components in our system, and all are working as expected with no errors (Note: error 460 is from ClaimMD and doesn't depend on our payload; it's "try later"). But we identified some settings adjustments that can improve the success rate: 1st: increase waits between batches, 2nd: improve scheduled retries for Monday and Tuesday.
For point 2, we created these two linear tickets https://linear.app/paradigmseniors/issue/RCM-919/improve-performance-for-eligibility-benefits-page-by-adding-indexes & https://linear.app/paradigmseniors/issue/RCM-920/improve-performance-for-eligibility-benefits-page
RCM-919 is already DONE, and RCM-920 is in Triage.