It seems like you are facing issues with the administrative notifications for the alerts on your web apps, especially for backups. According to the information you have provided, the alerts are working fine for the resources that are on cloud only systems, but not for the resource groups that are on Hybrid Live or Dev.
Based on the information from the fetched documents, it is recommended to use Azure Monitor based alerts as it offers multiple benefits. You can follow the steps mentioned in the article "Based on the information from the fetched documents, it is recommended to use Azure Monitor based alerts as it offers multiple benefits. You can follow the steps mentioned in the article "Switch to Azure Monitor based alerts for Azure Backup" to switch to Azure Monitor based alerts." to switch to Azure Monitor based alerts.
You can also follow the steps mentioned in the article "Monitor Azure Backup protected workloads" to monitor Azure Backup protected workloads.
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