Answer
Many functions of mcumgr will not work with WSL or GitBash. Serial communication isn't fully vetted with these terminal emulators. When using Windows, it's best to use mcumgr in the "command prompt" app.
Many functions of mcumgr will not work with WSL or GitBash. Serial communication isn't fully vetted with these terminal emulators. When using Windows, it's best to use mcumgr in the "command prompt" app.