When AC imports a plugin or theme through the legacy import endpoint, it generates package metadata for it on the fly and gives it a web DID, but that package overwrites any existing package that may have been imported already from its proper FAIR metadata. This would be solved by the simple optimization of not clobbering existing plugins/themes if the same slug and version already exists. If the version is updated though, there's not a lot that can be done except to wait for the package metadata to come in on the package import endpoint (see issue #359) and connect the package to the existing legacy metadata.