Hi, just an update, no connectivity out-of-the-box 
with 18.04:

Sep 06 07:02:06 msbi-corei NetworkManager[1299]: <info>  [1536210126.6615] device (ttyUSB0): Activation: starting connection 'E-Plus connection' (bfe0f53f-....-cafebf693838)
Sep 06 07:02:06 msbi-corei NetworkManager[1299]: <info>  [1536210126.6624] audit: op="connection-activate" uuid="bfe0f53f-ccd2-45b6-b35b-cafebf693838" name="E-Plus connection" pid=17739 uid=1000 result="success"
Sep 06 07:02:06 msbi-corei NetworkManager[1299]: <info>  [1536210126.6637] device (ttyUSB0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Sep 06 07:02:06 msbi-corei NetworkManager[1299]: <info>  [1536210126.6673] device (ttyUSB0): state change: prepare -> need-auth (reason 'none', sys-iface-state: 'managed')
Sep 06 07:02:06 msbi-corei NetworkManager[1299]: <info>  [1536210126.6774] device (ttyUSB0): state change: need-auth -> prepare (reason 'none', sys-iface-state: 'managed')
Sep 06 07:02:06 msbi-corei ModemManager[1205]: <warn>  (ttyUSB0): port attributes not fully set
Sep 06 07:02:09 msbi-corei ModemManager[1205]: <warn>  (ttyUSB0): port attributes not fully set
Sep 06 07:02:09 msbi-corei ModemManager[1205]: <warn>  (ttyUSB0): port attributes not fully set
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: state changed (locked -> initializing)
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <warn>  (ttyUSB0): port attributes not fully set
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <warn>  couldn't load Operator name: 'Operation not supported'
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <warn>  couldn't load current Bands: 'Unknown error'
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: state changed (initializing -> disabled)
Sep 06 07:02:13 msbi-corei NetworkManager[1299]: <info>  [1536210133.8852] modem["ttyUSB0"]: modem state changed, 'locked' --> 'disabled' (reason: unknown)
Sep 06 07:02:13 msbi-corei NetworkManager[1299]: <info>  [1536210133.8856] modem["ttyUSB0"]: modem state changed, 'disabled' --> 'enabling' (reason: user preference)
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: state changed (disabled -> enabling)
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <warn>  (ttyUSB0): port attributes not fully set
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <warn>  (ttyUSB2): port attributes not fully set
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <info>  Simple connect started...
Sep 06 07:02:13 msbi-corei ModemManager[1205]: <info>  Simple connect state (4/8): Wait to get fully enabled
Sep 06 07:02:14 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: 3GPP Registration state changed (unknown -> idle)
Sep 06 07:02:14 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: state changed (enabling -> enabled)
Sep 06 07:02:14 msbi-corei ModemManager[1205]: <info>  Simple connect state (5/8): Register
Sep 06 07:02:14 msbi-corei NetworkManager[1299]: <info>  [1536210134.5790] modem["ttyUSB0"]: modem state changed, 'enabling' --> 'enabled' (reason: user-requested)
Sep 06 07:02:15 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: 3GPP Registration state changed (idle -> registering)
Sep 06 07:02:15 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: 3GPP Registration state changed (registering -> home)
Sep 06 07:02:15 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: state changed (enabled -> registered)
Sep 06 07:02:15 msbi-corei NetworkManager[1299]: <info>  [1536210135.7173] modem["ttyUSB0"]: modem state changed, 'enabled' --> 'registered' (reason: unknown)
Sep 06 07:02:18 msbi-corei ModemManager[1205]: <info>  Simple connect state (6/8): Bearer
Sep 06 07:02:18 msbi-corei ModemManager[1205]: <info>  Simple connect state (7/8): Connect
Sep 06 07:02:18 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: state changed (registered -> connecting)
Sep 06 07:02:18 msbi-corei ModemManager[1205]: <warn>  Couldn't find associated cdc-wdm port for 'net/wwp0s20f0u9c2'
Sep 06 07:02:18 msbi-corei NetworkManager[1299]: <info>  [1536210138.1869] modem["ttyUSB0"]: modem state changed, 'registered' --> 'connecting' (reason: user-requested)

Sep 06 07:03:19 msbi-corei ModemManager[1205]: <info>  Modem /org/freedesktop/ModemManager1/Modem/2: state changed (connecting -> registered)
Sep 06 07:03:19 msbi-corei NetworkManager[1299]: <info>  [1536210199.1425] modem["ttyUSB0"]: modem state changed, 'connecting' --> 'registered' (reason: user-requested)
Sep 06 07:03:19 msbi-corei NetworkManager[1299]: <warn>  [1536210199.1428] modem-broadband[ttyUSB0]: failed to connect modem: Connection attempt timed out
Sep 06 07:03:19 msbi-corei NetworkManager[1299]: <info>  [1536210199.1430] device (ttyUSB0): state change: prepare -> failed (reason 'gsm-registration-timeout', sys-iface-state: 'managed')
Sep 06 07:03:19 msbi-corei NetworkManager[1299]: <warn>  [1536210199.1475] device (ttyUSB0): Activation: failed for connection 'E-Plus connection'
Sep 06 07:03:19 msbi-corei NetworkManager[1299]: <info>  [1536210199.1616] device (ttyUSB0): state change: failed -> disconnected (reason 'none', sys-iface-state: 'managed')