The Azure Serial console can be disabled and re-enabled for an entire subscription by using the following commands in the Azure CLI. To get the current status of the serial console in your subscripton use the following command:

$subscriptionId=$(az account show --output=json | jq -r .id)

az resource show --ids "/subscriptions/$subscriptionId/providers/Microsoft.SerialConsole/consoleServices/default" --output=json --api-version="2018-05-01" | jq .properties

To enable the serial console for a subscription, use the following commands:

$subscriptionId=$(az account show --output=json | jq -r .id)

az resource invoke-action --action enableConsole --ids "/subscriptions/$subscriptionId/providers/Microsoft.SerialConsole/consoleServices/default" --api-version="2018-05-01"

To disabled the serial console for a subscription, use the following commands:

$subscriptionId=$(az account show --output=json | jq -r .id)

az resource invoke-action --action disableConsole --ids "/subscriptions/$subscriptionId/providers/Microsoft.SerialConsole/consoleServices/default" --api-version="2018-05-01"