I have finally found out, why I do have always problem with Raspberry Pi OS Lite (previously Raspbian) and Bluetooth.
Something like:
bluetoothctl
Waiting to connect to bluetoothd...
or need to use sudo
for Bluetooth to work.
I am using Node-Red to detect beacons and other BTLE devices and for development of the Node-Red flow before porting them to Advantech 4G routers. Problem is that to make Bluetooth work was always a problem and after many steps I was just happy that I made it work and did not go back to investigate properly.
It happened today again, but I was probably searching and reading better and found the easy solution to the problem. Check this answer on Stackexchange.
Fix it:
In short the user does not belong into bluetooth
group by default and thus does not have privileges to use the resource. After adding your user to the group the easiest is to reboot or you need to logout and login.
sudo usermod -G bluetooth -a <username>
sudo reboot
That's it. Hope this helps others looking for a fix for Bluetooth on Raspberry Pi.