Great. The results you have there are expected, since you’re effectively disabling the graphics driver. But we can now find a better workaround & solution.
After installing the OS, boot up without adding the special parameter. You will likely reach a textured grey screen (because the login screen is being shown on the other display, which does not actually exist).
At this point press Ctrl+Alt+F2 and you should reach a textual login screen. Log in with your username and password. At the shell prompt, run:
ls /sys/class/drm/ and note the resultant text that appears.
I think one of the items listed there should be
card0-LVDS-1. If you don’t see that, just stop at this point and let me know what the results of the above command are.
Otherwise, proceed to run the
reboot command, and go back into grub and press ‘e’ to edit the boot entry as described above. But this time do not add
i915.modeset=0, instead, carefully add the following parameter exactly as written:
Now you should boot into Endless, the real display should be active & primary, and you should be able to change resolutions as normal.
You’ll probably have to manually add this parameter on every boot, but if you can confirm it’s working then I will show you how to make the parameter change permanent.
Also, if this works please make a diagnostic log from each affected computer model:
If you share the diagnostic logs here I can then modify the Linux kernel so that you do not need to add the special parameter in a future software update.