Deployment of Firewall ends with Provisioning state 'Updating' causing subsequent deployments to timeout and fail

Hello @Derek Pilat , Thank you for reaching out to us.

As the resource is stuck in updating state, you will not be able to delete it until it is in succeeded or failed state. We have seen this issue sometimes gets resolved if you run a List and an Update command on the Azure Firewall
You can run any of the Azure Firewall CLI commands. For eg you can run following CLI commands using Azure Cloud Shell

az network firewall application-rule list --collection-nam --firewall-name --resource-group  

AND

az network firewall policy rule-collection-group collection rule update -g {rg} --policy-name {policy} --rule-collection-group-name {rcg} --collection-name {cn} -n {rule_name} --target-fqdns XXX  

If the state of your Firewall still remains at "updating", then it would need to be fixed from the backend. So, if you have a support plan, I request you file a support ticket, else please do let us know, we will try and help you get a one-time free technical support (Please refer to my private message below). The support engineer will also help you to understand why this issue is happening frequently and what is the exact cause.

Hope this helps! Please let me know if you have any additional questions. Thank you!