Huawei e3372 cannot automate interface up

There is "TP-Link TL-WR902AC v3" with huawei e3372 modem.
I configured this based on https://openwrt.org/docs/guide-user/network/wan/wwan/ethernetoverusb_ncm and it almost work.
"Almost because" I cannot make that wwan interface would be started automatically.
Problem is that my ISP quite often does not give me IP address at first time.
So I have to do ifup /ifdown sequence.
Manually I can achieve state where interface is up and running.
But I cannot make it automatically.
It seems that /etc/init.d/ncm-network during boot is called from two places, and I have some kind of race condition.
Is any way to check what procd or other service manager is calling?
Sorry for so vague descripiton but I am not even sure what to ask.

After some digging I found that (probably) main problem is with '/dev/cdc-wdm0' device. After some init sequeces this device got stuck. I switched device to /dev/ttyUSB0, and although this is still unreliable (on device shows sometimes diagnostic messages) but is far better that with /dev/cdc-wdm0 device.

config interface 'wwan'
        option proto 'ncm'
	option auto 0
        option ifname 'wwan0'
#        option device '/dev/cdc-wdm0'
        option device '/dev/ttyUSB0'
	option apn 'a2mobile.pl'
	option pincode 'xxxx'
        option delay '10'
	option dhcp '1'