I'm facing the same error and was wondering if you know if your mentioned issue form January still persists ?
To be more precise the API is giving me the following error msg:
The gateway deployment operation failed due to an intermittent error. Please try again. (Code: VmssGatewayDeploymentFailed)
I have checked my Status Health and the global Azure Status, but there is no ongoing incident that's affecting Virtual Networks or Virtual Network Gateways.