Hello Hoang Minh Duc (EBS.ERP),
Welcome to the Microsoft Q&A and thank you for posting your questions here.
I understand that you would like to affirm if there any conflict between configuration changes in Azure Update Manager affecting the VM backup process in Azure backup.
Regarding your explanations, there could be a few reasons why the backup is taking so long and not completing, not only changes in Azure Update Manager. Though, configuration change in Azure Update Manager shouldn’t typically interfere with the backup process but unexpected behaviors can occur.
I will advise to check performance bottlenecks on the VM itself and antivirus software or other background processes can interfere with the backup process - https://video2.skills-academy.com/en-us/azure/backup/backup-azure-troubleshoot-slow-backup-performance-issue
Secondly, backup agent on the VM itself can slow down the process due to IOPS limitations - https://github.com/MicrosoftDocs/azure-docs/blob/main/articles/backup/backup-azure-troubleshoot-slow-backup-performance-issue.md
Also, try to check for network-related issues that might be causing delays in data transfer to the vault - https://video2.skills-academy.com/en-us/answers/questions/1327544/transfer-data-to-vault-is-taking-long-time-to-comp and configuration settings in Azure Update Manager to ensure there are no conflicts or settings that might be affecting the backup process - https://video2.skills-academy.com/en-us/azure/update-manager/manage-update-settings?tabs=manage-single-overview%2Cmanage-scale-overview
Finally, in the Update Setting of your VM > Re-enable the Periodic Assessment, turn it back on and observe if it makes a difference in your backup process timing. Sometimes, the combination of configurations can lead to unexpected conflicts.
I hope this is helpful! Do not hesitate to let me know if you have any other questions.
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