My team has developed an app with a Matter commissioner feature (for own ecosystem) using the Matter framework on the MatterSupport extension.
Recently, we've noticed that commissioning Matter devices with the MatterSupport extension has become very unstable. Occasionally, the HomeUIService stops the flow after commissioning to the first fabric successfully, displaying the error: "Failed to perform Matter device setup: Error Domain=HMErrorDomain Code=2." (normally, it should send open commissioning window to the device and then add the device to the 2nd fabric). The issue is never seen before until recently few weeks and there is no code changes in the app. We are suspected that there is some data that fail to download from the icloud or apple account that cause this problem.
For evaluation, we tried removing the HomeSupport extension and run the Matter framework directly in developer mode, this issue disappears, and commissioning works without any problems.