I delete the edid via "getedid delete" and reboot the PI. Nothing has changed.
Nothing should change. The RPi5 should continue using 1080p desktop resolution; this is the default and best setting. You should now be able to go into Kodi video settings and add 3840x2160 resolutions to the mode whitelist so that Kodi can use them for 4K playback. See https://wiki.libreelec.tv/configuration/4k-hdr for more info.
I would remove the getedid stuff unless you plan to boot the RPi5 with the AVR disconnected, it's not really needed.