I think either the WWDR is working because your cert is now valid or you didn't need it to begin with. The issues with signing might just be related to your version of XCode, it sounds like you're doing everything I had to do. Sorry I couldn't help more, hopefully apple addresses this issue.

I'm on XCode 11.4 When you open your keychain and look at the certificate, does it say it's valid? Mine was not saying it was valid until I installed the WWDR certificate above. What you are seeing in XCode is the same thing I was seeing when trying automatic signing. The cert was showing up twice and one was greyed out.

@orks I installed the WWDR certificate in the link. Then I went into Xcode and created a certificate with automatic signing. That doesn't work because it says it can't find the private key, so I went back to previous screen and selected manual signing and chose the same certificate and it works. I had to do the same thing again today for a different app. Make sure that your provisioning profile is updated with the new certificate as well, you can update the profile in the apple developer console.

After a few frustrating hours, I found I had to install apples latest WWDR certificate: https://www.apple.com/certificateauthority/AppleWWDRCAG3.cer Automatic signing still is not working, but at least with this I can now manually sign.

Automatic signing broken for me as well, Xcode 11.4