There is definitely something odd going on here. I am seeing different behaviors across different systems: I have at least one macOS 12.0.1 system where the Launcher app seems to work OK with the current 3.10.1 (as long as the Terminal.app is already running) but then on some other 12.0.1 systems and on an 11.6.1 system it fails as you describe it. This is also across a mixture of Intel and Apple Silicon systems and VMs so no obvious correlation there. Launching via IDLE does seem to work properly on the systems I've tested so perhaps that might be a temporary workaround as well as just manually running the script in a Terminal.app window. I am going to close this issue as a duplicate of Issue40477 and am bumping the priority with the aim to have a fix prior to the next round of releases in early January.