Comment 9 for bug 1949677

Thanks. Those logs say the preferred mode is 1920x1080 so indeed you will see some aspect distortion if that's referring to a 1920x1200 monitor...

Next we need to find out if either:

(a) the incorrect preferred mode is coming from the kernel; or

(b) plymouth is applying the preferred mode of the laptop panel to the external monitor.

Please run 'drm_info' while only the external monitor is connected and the laptop lid is still closed, and attach the output here. drm_info is not in the archive until hirsute but it's a very simple program you should be able to get running: https://launchpad.net/ubuntu/+source/drm-info