HL7588 sending Attach command reports Detached

Issue:
I am using ModemManager to set-up the modem using MBIM and when it sends Attach command the modem reports “detached”. I have tested this outside ModemManager and found out that even though the modem is attached (replied to my query) by just sending the attach command it reports detached !

Expected behavior:
When the modem is attached and it receives the attach command it should report attached even though it does not do any further action.

The QUERY shows the modem is attached:

$ sudo ./umbim -d /dev/cdc-wdm1 attached
  nwerror             : 0x0000 - unknown
  packetservicestate  : 0x0002 - attached
  uplinkspeed         : 50000000
  downlinkspeed       : 100000000

However sending SET (immediately after QUERY) reports as detached:

$ sudo ./umbim -d /dev/cdc-wdm1 attach
  nwerror             : 0x0000 - unknown
  packetservicestate  : 0x0004 - detached
  uplinkspeed         : 0
  downlinkspeed       : 0

ModemManager (from freedesktop.org project and widely used in Ubuntu/Debian etc. distros):

<info>  [1570205988.969600] Simple connect started...
<debug> [1570205988.975909]    PIN: unspecified
<debug> [1570205988.977402]    Operator ID: unspecified
<debug> [1570205988.977983]    Allowed roaming: yes
<debug> [1570205988.978551]    APN: internet
<debug> [1570205988.979141]    IP family: ipv4
<debug> [1570205988.979739]    Allowed authentication: unspecified
<debug> [1570205988.981007]    User: unspecified
<debug> [1570205988.981584]    Password: unspecified
<info>  [1570205988.982157] Simple connect state (4/8): Wait to get fully enabled
<info>  [1570205988.982787] Simple connect state (5/8): Register
<debug> [1570205988.983394] Already registered in network '302300', automatic registration not launched...
<info>  [1570205988.984744] Simple connect state (6/8): Bearer
<debug> [1570205988.985308] Using already existing bearer at '/org/freedesktop/ModemManager1/Bearer/0'...
<info>  [1570205988.985899] Simple connect state (7/8): Connect
<debug> [1570205988.986550] Connecting bearer '/org/freedesktop/ModemManager1/Bearer/0'
<info>  [1570205988.988012] Modem /org/freedesktop/ModemManager1/Modem/0: state changed (registered -> connecting)
<debug> [1570205988.989390] Launching connection with data port (net/wwp0s20f0u9)
<debug> [1570205988.990006] Activating packet service...
[/dev/cdc-wdm0] Sent message...
<<<<<< RAW:
<<<<<<   length = 52
<<<<<<   data   = 03:00:00:00:34:00:00:00:21:00:00:00:01:00:00:00:00:00:00:00:A2:89:CC:33:BC:BB:8B:4F:B6:B0:13:3E:C2:AA:E6:DF:0A:00:00:00:01:00:00:00:04:00:00:00:00:00:00:00
[/dev/cdc-wdm0] Sent message (translated)...
<<<<<< Header:
<<<<<<   length      = 52
<<<<<<   type        = command (0x00000003)
<<<<<<   transaction = 33
<<<<<< Fragment header:
<<<<<<   total   = 1
<<<<<<   current = 0
<<<<<< Contents:
<<<<<<   service = 'basic-connect' (a289cc33-bcbb-8b4f-b6b0-133ec2aae6df)
<<<<<<   cid     = 'packet-service' (0x0000000a)
<<<<<<   type    = 'set' (0x00000001)
<<<<<< Fields:
<<<<<<   PacketServiceAction = 'attach'
[/dev/cdc-wdm0] Received message...
>>>>>> RAW:
>>>>>>   length = 76
>>>>>>   data   = 03:00:00:80:4C:00:00:00:21:00:00:00:01:00:00:00:00:00:00:00:A2:89:CC:33:BC:BB:8B:4F:B6:B0:13:3E:C2:AA:E6:DF:0A:00:00:00:02:00:00:00:1C:00:00:00:00:00:00:00:04:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
[/dev/cdc-wdm0] Received message (translated)...
>>>>>> Header:
>>>>>>   length      = 76
>>>>>>   type        = command-done (0x80000003)
>>>>>>   transaction = 33
>>>>>> Fragment header:
>>>>>>   total   = 1
>>>>>>   current = 0
>>>>>> Contents:
>>>>>>   status error = 'Failure' (0x00000002)
>>>>>>   service      = 'basic-connect' (a289cc33-bcbb-8b4f-b6b0-133ec2aae6df)
>>>>>>   cid          = 'packet-service' (0x0000000a)
<debug> [1570205988.998257] Packet service update:
<debug> [1570205988.998850]          state: 'detached'
<debug> [1570205988.999485]     data class: '(null)'
<debug> [1570205989.000785]         uplink: '0' bps
<debug> [1570205989.001394]       downlink: '0' bps
<debug> [1570205989.001980] Couldn't connect bearer '/org/freedesktop/ModemManager1/Bearer/0': 'Failure'
<info>  [1570205989.002596] Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> registered)
<debug> [1570205989.003413] Couldn't connect bearer: 'Failure'