@treebeard : Thanks for sharing the reason! Hopefully it will help others to prevent this experience.

What does exacly exec do?

I ask, because sh doesn't work for my script like . does.

I'm also interested as I want to run VPN on boot and keep it always on.

Here are my scrips and other information.

Also, what are the nmcli commands that enable cellular data? I tried to find it and I'm run out of ideas.