"Backup Pre-check" Status detection
Currently we don't have any way to detect "Backup Pre-check" failure or warning. To keep backup operation in stable condition, we should have detection function.
Backup pre-check is already available in the Azure portal. Are you referring to alerts/notification or a programmatic feedback while using Powershell/CLI?
Uffe Sommerlund commented
backup pre-check what does that include ?
network, dns, port check.