We have an Automated Attestation signing app based on the C# sample from msdn. It's been working for the past 3 years with only minor tweaks here and there, refresh a client secret, etc. It's now failing with an "HTTP 503 Service Unavailable" response to a properly formed and authorized request and has been for at least 2 days. This has worked as recently as 2 weeks ago. Does anybody else automate submissions and if so do you have a way to see if automated Attestation submission is still working for you?