EC25 / Roaming SIM card - Data run through dongle for only 1 minutes every 10 minutes

Hello, running a roaming SIM card on a Quectel EC25 USB dongle, i got issue with traffic running through interface for only a minute every 10minutes.

AT+QCFG=“nwscanmode”,3 and AT+QCFG=“roamservice”,2 are sent once on every boot.

After pppd startup, i let a ping command running : “ping -Ippp0 1.1.1.1” to check connectivity (an ICMP packet is sent every seconds). Every ~10minutes, nothing goes through interface anymore until everything is unlocked for a minute (~350/400 first blocked ping get an echo, and new pings are received within ~60ms)

am335x-evm:~# ping -Ippp0 1.1.1.1
PING 1.1.1.1 (1.1.1.1): 56 data bytes
64 bytes from 1.1.1.1: seq=2 ttl=52 time=754998.369 ms
64 bytes from 1.1.1.1: seq=11 ttl=52 time=746020.193 ms
64 bytes from 1.1.1.1: seq=10 ttl=52 time=747020.660 ms
[…]
64 bytes from 1.1.1.1: seq=368 ttl=52 time=389088.645 ms
64 bytes from 1.1.1.1: seq=369 ttl=52 time=388088.285 ms
64 bytes from 1.1.1.1: seq=372 ttl=52 time=385087.153 ms
64 bytes from 1.1.1.1: seq=758 ttl=52 time=67.568 ms
64 bytes from 1.1.1.1: seq=759 ttl=52 time=75.116 ms
[…]
64 bytes from 1.1.1.1: seq=780 ttl=52 time=78.638 ms
64 bytes from 1.1.1.1: seq=781 ttl=52 time=59.371 ms
64 bytes from 1.1.1.1: seq=786 ttl=52 time=937.303 ms
64 bytes from 1.1.1.1: seq=787 ttl=52 time=62.133 ms
64 bytes from 1.1.1.1: seq=788 ttl=52 time=94.803 ms
[…]
64 bytes from 1.1.1.1: seq=825 ttl=52 time=61.519 ms
64 bytes from 1.1.1.1: seq=826 ttl=52 time=96.949 ms
64 bytes from 1.1.1.1: seq=828 ttl=52 time=753925.792 ms
64 bytes from 1.1.1.1: seq=831 ttl=52 time=750924.829 ms
[…]
64 bytes from 1.1.1.1: seq=1190 ttl=52 time=391957.238 ms
64 bytes from 1.1.1.1: seq=1183 ttl=52 time=398959.747 ms
64 bytes from 1.1.1.1: seq=1582 ttl=52 time=69.706 ms
64 bytes from 1.1.1.1: seq=1583 ttl=52 time=68.627 ms
[…]
64 bytes from 1.1.1.1: seq=1605 ttl=52 time=60.281 ms
64 bytes from 1.1.1.1: seq=1606 ttl=52 time=66.876 ms
64 bytes from 1.1.1.1: seq=1611 ttl=52 time=742.406 ms
64 bytes from 1.1.1.1: seq=1612 ttl=52 time=53.800 ms
64 bytes from 1.1.1.1: seq=1613 ttl=52 time=68.663 ms
[…]
64 bytes from 1.1.1.1: seq=1650 ttl=52 time=58.991 ms
64 bytes from 1.1.1.1: seq=1651 ttl=52 time=60.496 ms
64 bytes from 1.1.1.1: seq=1652 ttl=52 time=755053.093 ms
64 bytes from 1.1.1.1: seq=1654 ttl=52 time=753053.321 ms
[…]
64 bytes from 1.1.1.1: seq=2023 ttl=52 time=384077.794 ms
64 bytes from 1.1.1.1: seq=2032 ttl=52 time=375074.703 ms
64 bytes from 1.1.1.1: seq=2408 ttl=52 time=57.785 ms
64 bytes from 1.1.1.1: seq=2409 ttl=52 time=55.468 ms
[…]
64 bytes from 1.1.1.1: seq=2430 ttl=52 time=64.746 ms
64 bytes from 1.1.1.1: seq=2431 ttl=52 time=75.461 ms
64 bytes from 1.1.1.1: seq=2437 ttl=52 time=161.722 ms
64 bytes from 1.1.1.1: seq=2436 ttl=52 time=1163.761 ms
64 bytes from 1.1.1.1: seq=2438 ttl=52 time=62.156 ms
64 bytes from 1.1.1.1: seq=2439 ttl=52 time=62.889 ms
[…]
64 bytes from 1.1.1.1: seq=2475 ttl=52 time=59.866 ms
64 bytes from 1.1.1.1: seq=2476 ttl=52 time=59.501 ms
64 bytes from 1.1.1.1: seq=2477 ttl=52 time=754944.587 ms
64 bytes from 1.1.1.1: seq=2478 ttl=52 time=753964.932 ms

This issue is not seen using a local operator SIM card on the same dongle; or the same SIM card on a Huawei dongle.

Any idea of what may cause this issue, and how i can fix it ?

Best regards,
Romain