Realtek RTL8822CE Bluetooth adapter not found sometimes

Sometimes the order the network modules are loaded can create conflicts that can cause either your WiFi or BT to fail to start correctly.

You can try the following test:

The command below will automatically generate an /etc/modprobe.d/blacklist.conf file that will blacklist your bluetooth modules and prevent them from loading at startup.

sudo echo -e "blacklist btusb\nblacklist btrtl" | sudo tee -a /etc/modprobe.d/blacklist.conf

Power down your computer completely after running that command, then restart your computer. Once your computer is fully restarted, you can attempt to manually start your Bluetooth connection with the following command:

bash -c "bluetoothctl power off; sleep .5; sudo systemctl stop bluetooth; sleep .5; sudo rfkill unblock bluetooth; sleep 1; sudo modprobe btrtl; sleep 1; sudo modprobe btusb; sleep 2; sudo systemctl start bluetooth; sleep 2; bluetoothctl power on"

If your BT is still not working after running that command, try running this:

systemctl restart NetworkManager

If that procedure does not work, then you can reverse the changes you made. Remove the blacklist btusb and blacklist btrtl lines from the /etc/modprobe.d/blacklist.conf file. After removing both of those lines from the conf file, save the changes and reboot. Your computer should be as before after rebooting.

It is possible that tlp or other laptop power management software can interfere with bluetooth operation. You might want to double check that your BT is excluded from all power management options you can locate.