Starting January 28, 2021, the digital certificates you use to sign your software for installation on Apple devices, submit apps to the App Store, and connect to certain Apple services will be issued from a new intermediate Apple Worldwide Developer Relations certificate (expiring 2030). This new intermediate certificate will not affect the availability or functionality of apps you’re already distributing on the App Store. And you can continue to use your existing certificates until they expire.
If you’re running Xcode 11.4.1 or later, you’ll receive the updated certificate automatically when you sign an app after January 28, 2021. If you’re running an earlier release of Xcode and need to generate new certificates, download and install the new intermediate certificate and utilize the command line to sign your app. You can also archive your build with your existing Xcode version and sign it for distribution with Xcode 11.4.1 or later.
The current intermediate certificate (expiring in 2023), will continue to issue certain Apple services certificates, including Apple Push Notification service (APNs) SSL certificates and Apple Wallet pass signing certificates. Keep both versions installed on your development systems and servers until later this year.
For a few days now it is necessary. With certificates and provision files made months ago, everything works normally, but with certificates created two or three days ago, it does not work, and it is because it is necessary to install the new certificate (which expires in 2030) in the MAC certificate keychain, because the NEW certificates are validated with this one. Once this is done, everything works normally.
The hosted builders run an updated builder software that includes the new certificate. Previously builder1 ran an older version by mistake.
I will release a new version of B4i soon and it will include the updated certificate. As @Jaume Guillem wrote, the new certificate is only required for new developer certificates.