We got a reply from technical team on 17th July which resolved our issue. It is likely this got through the net in previous releases, but not after we had updated to 2026 SDK's - which explains the timing. The install-path  was set incorrectly.                                                  Please make your install-path to be just /Applications.

Having a similar issue... https://developer.apple.com/forums/thread/836860

Thanks for the reply and the information, very much appreciated!