The 429 error occurs when you have too many deployments/failed deployments of an app service plan within a short period of time. This causes the system to throttle any additional deployments for the next 48 hours. This limit is per region, which is why you were able to use other regions or subscriptions.
If this occurs, you will need to wait 48 hours to complete a deployment in that region or contact support to see if they will remove the throttle.
let us know if the above helps or you need further assistance on this issue.