TP-Link MR200 v4. DHCP client not working with wwan interface

Installing and Using OpenWrt
1

I have compiled a firmware based on 19.07.8 to my MR200 v4.
But I can´t get the DHCP client, udhcpc, to work with my LTE modem.
Why is not udhcpc able to lease an IP address and why is not ´qmicli -d /dev/cdc-wdm0 --device-open-net="net-raw-ip|net-no-qos-header"´ working?

After a power reset the modem is in Shutting-down state.
This is my steps to get it up.

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --dms-get-operating-mode
[/dev/cdc-wdm0] Operating mode retrieved:
        Mode: 'shutting-down'
        HW restricted: 'no'

root@OpenWrt:~# ifconfig wwan0 down
root@OpenWrt:~# echo Y > /sys/class/net/wwan0/qmi/raw_ip
root@OpenWrt:~# cat /sys/class/net/wwan0/qmi/raw_ip
Y
root@OpenWrt:~# ifconfig wwan0 up

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --wda-get-data-format
[/dev/cdc-wdm0] Successfully got data format
                   QoS flow header: no
               Link layer protocol: 'raw-ip'
  Uplink data aggregation protocol: 'disabled'
Downlink data aggregation protocol: 'disabled'
                     NDP signature: '0'

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --wds-get-profile-list=3gpp
Profile list retrieved:
        [1] 3gpp -
                APN: 'internet'
                PDP type: 'ipv4'
                PDP context number: '1'
                Username: ''
                Password: ''
                Auth: 'none'
                No roaming: 'no'
                APN disabled: 'no'

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --dms-set-operating-mode=online
[/dev/cdc-wdm0] Operating mode set successfully
root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --dms-get-operating-mode
[/dev/cdc-wdm0] Operating mode retrieved:
        Mode: 'online'
        HW restricted: 'no'

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --wds-get-current-settings
[/dev/cdc-wdm0] Current settings retrieved:
           IP Family: IPv4
        IPv4 address: 100.104.179.64
    IPv4 subnet mask: 255.255.255.128
IPv4 gateway address: 100.104.179.65
    IPv4 primary DNS: 195.54.122.211
  IPv4 secondary DNS: 195.54.122.221
                 MTU: 1500
             Domains: none

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --device-open-net="net-raw-ip|net-no-qos-header"
error: no actions specified

root@OpenWrt:~# udhcpc -n -i wwan0
udhcpc: started, v1.30.1
udhcpc: sending discover
udhcpc: sending discover
udhcpc: sending discover
udhcpc: no lease, failing

Modem information:

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --dms-get-manufacturer
[/dev/cdc-wdm0] Device manufacturer retrieved:
        Manufacturer: 'QUALCOMM INCORPORATED'

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --dms-get-model
[/dev/cdc-wdm0] Device model retrieved:
        Model: '0'

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --dms-get-revision
[/dev/cdc-wdm0] Device revision retrieved:
        Revision: 'MPSS.JO.1.2.c1-00145-9607_GEN_PACK-2  1  [Aug 03 2016 17:00:00]'

root@OpenWrt:~# qmicli -d /dev/cdc-wdm0 --dms-get-hardware-revision
[/dev/cdc-wdm0] Hardware revision retrieved:
        Revision: '10000'
2

If I manually set the IP address and the route I can access internet.

Then I found:
"LTE module does not support DHCP so it must be configured via QMI."
you must change the default value of
"dhcp" option in QMI protocol configuration options from 1 to 0 so the system is using uqmi and not dhcp

How will UQMI handle the assignment of IP address and route?