As requested by Alexander, I am attaching an annotated log of modem-manager output, along with that of related commands, from a complete series of tests, starting with clean reboot, working through failures and finally working after creating the ttyACM0 symlink.
As requested by Alexander, I am attaching an annotated log of modem-manager output, along with that of related commands, from a complete series of tests, starting with clean reboot, working through failures and finally working after creating the ttyACM0 symlink.