The picture on the HDMI in the 1280x720 resolution looks correct only until the Weston desktop starts. After that, the picture shatters into pieces and starts trembling.
This can be reproduced on the i.MX8M EVK board with the fsl-image-qt5-validation-imx-xwayland-imx8mqevk.sdcard.bz2 image from L4.9.88_2.0.0_images_MX8MQ.tar.gz.
To reproduce this issue on a FullHD or 4K monitor, /etc/xdg/weston/weston.ini should be updated as follows to avoid switching to another resolution in Weston:
The same issue is observed in the 720x576@50hz mode.
Is it a known issue? How can this be fixed?