If ir-keytable -p all -t didn't output anything then either eventlircd or kodi were running in the background or the remote uses an odd protocol that's not supported by in-kernel decoding.
I haven't looked in detail at your lircd.conf file but it looks like it might indeed by the Panasonic protocol, which isn't supported (yet).
So, just use your lircd.conf file, you only have to change the KEY_ names to match the official key names input-event-codes.h\linux\uapi\include - kernel/git/torvalds/linux.git - Linux kernel source tree
In LibreELEC 8.2 you have to enable Lirc in LibreELEC Settings, in LE 9 and the current alpha versions lirc will be started automatically when a /storage/.config/lircd.conf file is present.
Also read the info in the wiki Infrared Remotes [LibreELEC.wiki]
so long,
Hias