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2023-07-29 02:55:49.891 T:757 debug <general>: CDRMUtils::SetMode - found crtc mode: 3840x2160 @ 30 Hz
EDID data in Kodi.log shows 1080/3840 modes fine but this ^ looks like it's trying to set 4K GUI which won't work as the silicon only supports 1080p on the GUI plane. Have you fiddled with the GUI settings on the other monitor? .. because by default we set the GUI to 1080p. If no, I can't explain, but perhaps try clearing display settings (stop kodi, delete guisettings.xml, restart kodi) or force the initial DRM output to 1080p by appending "video=HDMI-A-1:1920x1080M@60" to kernel boot params in extlinux.conf.