WAN issues obtaining 3G connection

Hi there!

I have a HDRM200 (a chinese OpenWRT router), and i have a big issue with this:
-The router is configured to auto-detect the wan connection (3G or Ethernet), the APN is well setted too.
-An Auto-reboot is programmed (now, by testing, each 1 hour)
-At first instance, i have internet connection, the router obtains all the IP config from the 3G Network, everything goes fine.
-When the router auto-reboots, it never gets againt the IP or WAN configuration from the 3G APN, so i don't have internet again unless i manually reboot the router (and some times, that doesn't work either).

Any suggestions of what it would be the cause of this??

Thank you.

When you say manual reboot, do you mean rebooting it via the software (let that be Luci or SSH), or do you recycle the power?

And after "auto-reboot", what happens if you unplug and re-plug the USB 3G dongle?

Also would the autoreboot happens if you don't have the USB dongle plugged?

Are the interval between the reboots exactly the same, so you have reason to believe it's somewhere set-up to auto reboot, or does it vary so it could be regularly crashing?

You may also want to mention the software version.

Would you check 192.168.1.1/cgi-bin/luci/admin/system/crontab to see if such reboot is there as scheduled task?

Avoid rebooting. There's no reason to schedule an hourly reboot.

An important point is that the 3G/4G modem card has its own separate CPU and OS and has to stay in sync with the main OS. The connection between the two is USB. There are different protocols used on the USB though.

hi, thank you everyone for your reply.

Mi modem it's a HDRM200, uses the MT7620, the 3g/4G module is embedded on the board not with a USB dongle.

I've looking through the SSH, and i can't se a etc/config folder or similar.
I access to it by web (192.168.0.1/home.asp)

Reading the system log, i saw that is warning an upstream issue.
I've generated the same problem by activating and deactivating the wifi, looks like it gets stuck and it's not capable to get the ip configuration from the 4G ISP.

What do you think?

Ok, finally i found it has a busybox system.
Is there anyway to replace it by Luci for example?