A Muse bwrap line follows the binary path, and unrestricted is rejected
The permissions page tells you to pass --sandbox-network unrestricted when a Muse Code session should have full network access. It calls enabled the earlier name, and it says that earlier name still works. On Muse Code 1.4.14 the value unrestricted never starts a session. muse exec exits 2 and prints the three names it will accept: restricted, enabled, and proxy-only.
A later line, printed only after a session has started, tells you to install the distribution bwrap package. On this host that line tracked where the binary file resolved. It did not track whether bwrap was on PATH. The same file, with the same missing package, printed the line from /tmp and omitted it from a directory outside /tmp and outside TMPDIR. Both runs printed echo: ping and exited 0. Neither run executed a shell command.