gst-launch: waylandsink rendering scaled down

Got an i.MX8Plus with scarthgap yocto build, linked to camera and LCD display (resolution 1280x720), running:

gst-launch-1.0 -e -v v4l2src device=/dev/video0 ! video/x-raw, width=1920, height=1080 ! glimagesink render-rectangle='<0, 0, 1920, 1080>'

video/image shown on the LCD seems in scale (seems cropped from 1920x1080 to 1280x720), although the ‘origin’<0,0> seems changing or floating to different places when re-run each time. Picture shown below:

But if just replace the glimagesink with waylandsink:

gst-launch-1.0 -e -v v4l2src device=/dev/video0 ! video/x-raw, width=1920, height=1080 ! waylandsink render-rectangle='<0, 0, 1920, 1080>'

the video/image clearly shown on the LCD as scaled-down (around maybe 1/3):

Some online discussions suggested to check the weston.ini file: initially the file has no [output] section related to the LCD display; and even after I added the section with:

[output]
name=card0-DSI-1
mode=1280x720@60

waylandsink test always have image scaled down shown on the LCD (i.e. the weston.ini has no effect), where does wayland gets the scale-down setting?

Anyone has such experience, any insight, please?

BR
Jim