Hi all,
Similar situation here, I had a pretty outdated LibreElec install and upgraded to 9.2.4 on an RPi 3B+. Bluetooth was then suddenly reported as "de-activated" (or similar wording) - no amount of fiddling with the LibreElec settings achieved anything. After some poking around, it turns out that this was caused by the use of `dtoverlay=disable-wifi` in my `config.txt`. Commenting out the overlay restored BT functionality and allowed me to perform the usual actions available from the BT LibreElec config screen.
The sad thing is my reason for disabling WiFi was that when both WiFi and BT are activated at the same time in `config.txt` (regardless of LibreElec settings), Bluetooth audio is so choppy as to be unusable (I understand this is a known limitation of the RPi), disabling WiFi made it good enough for my purposes.
So I hope this helps (at least some of) those who lost their BT, and maybe inspires someone to suggest an alternative way to get decent BT audio on 9.2.4
Cheers!