Yup - tried that too. I’ve tried every method I could Google:
- ifconfig
- udev
- fw_setenv
- autostart
- systemd
The problem is not CoreELEC, it’s something with the box itself. As @anon88919003 pointed out, these boxes fall somewhere outside the norm and I personally believe it’s how the manufacturer built them. One post I came across is the Khardas KVIM (something like that) had a similar problem but fw_setenv (for them, it’s just setenv) is able to solve it but didn’t work for me.
In the end, I’m an edge-case - I simply revoke the commit in question (which is to generate MAC via CPU serial #) and compile my own copy, no biggie.