On October 20th, Aptos released a report on the mainnet event yesterday, stating that the Aptos network began experiencing transaction delays around 16:15 PDT on October 18th (07:15 Beijing time on October 19th). The transaction load was not the issue in this event, and submitted transactions were not lost or forked.

The problem was caused by non-deterministic code, which has now been fixed. The issue was resolved around 12:30 Beijing time on October 19th. On August 22nd, Aptos' core code repository submitted performance-based code changes, and on October 16th, the FeeStatement activity went live, providing detailed information on transaction fees/refunds. The initial code changes introduced non-determinism that was only revealed by FeeStatement.

After identifying the actual event output differences for non-deterministic transaction execution, the problem was traced back to the FeeStatement event and code changes. Meanwhile, a developer began simulating transactions through code changes to recover mapping changes, repeating them to ensure consistent results. Additionally, the recovery submitted by the code has been implemented, and docker builds are being made for validator operators, with a new version to be released later.