Wait about 20h before you try the latest LE12 nightly from here https://test.libreelec.tv/12.0/RPi/RPi5/
New images are currently being built and they include a fix for the "no display" issue on a KDL-46Z5500 - see bug report here https://forums.raspberrypi.com/viewtopic.php?p=2190093#p2190093
so long,
Hias