Adding this to one of the few posts of this topic that are still open. Here’s what the problem was for me:
My understanding is that the distribution certificate added to the temporary keychain is signed by an authority that doesn’t exist by default (at least on my fresh install of Monterey). So when the build process checks whether the import has been successful, it fails because the cert isn’t trusted.
This is the authority certificate that was missing for me https://www.apple.com/certificateauthority/AppleWWDRCAG3.cer
After importing this into my system keychain, the error was gone.