Cannot connect to BLE device on Raspberry Pi

Fixed the connection refused (111) issue in my raspberry pi 3B running raspbian buster by Updating/installing BlueZ via apt-get

> sudo apt-get install --no-install-recommends bluetooth

and re running

> sudo gatttool -t random -b E9:1C:89:B7:16:F9 -I

I was able to connect via Bluetooth from Raspberry to my Android device using gatttool after setting the LE address type to random with the -t random argument, i.e. :

sudo gatttool -t random -b DD:9D:0B:43:A1:77 -I
connect

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From gatttool man

--t, ---addr-type=[public | random] 
# Set LE address type. Default: public

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USAGE gatttool [OPTION...]

 Help Options:
     -h, --help                                  Show help options
     -h, --help                                  Show help options
     --help-all                                  Show all help options
     --help-gatt                                 Show all GATT commands
     --help-params                               Show  all  Primary  Services/Characteristics
   arguments
     --help-char-read-write                       Show  all  Characteristics Value/Descriptor
   Read/Write arguments

   Application Options:
     --i, ---adapter=hciX                        Specify local adapter interface
     --b, ---device=MAC                          Specify remote Bluetooth address
     --t, ---addr-type=[public | random]         Set LE address type. Default: public
     --m, ---mtu=MTU                             Specify the MTU size
     --p, ---psm=PSM                             Specify the PSM for GATT/ATT over BR/EDR
     --l, ---sec-level=[low | medium | high]     Set security level. Default: low
     --I, ---interactive                         Use interactive mode

I got it running with:

btmgmt le on

By default GATT is not enable. Add the below lines to /etc/bluetooth/main.conf

EnableLE = true           // Enable Low Energy support. Default is false.
AttributeServer = true    // Enable the GATT attribute server. Default is false.