RUTM30 modem problem after FW update

Networking Solutions Issue
1

Hello,

I am experiencing a persistent internal modem problem on a RUTM30 which started immediately after a modem firmware update. Before the modem update the router was working normally.

I got sometimes notification that the intern modem is unreachable (unexpected shutdown)

The issue persists after factory reset and clean configuration.

System firmware: RUTM_R_00.07.20.3
Modem firmware: RG520NEBDCR03A05M4G

Sim card is working (tried it in my phone) i also tried instead a Esim→didn’t work

My problem is nearly the same issue like this: RUTX50 internal modem unstable after RG520 modem firmware update – SIM failure, gsmctl N/A, no registration

Thank you

2

I think they’re released a buggy modem firmware.

4

Any possibility to downgrade the modem firmware?

5

Hello,

i’ve found a workaround for the people with the modem firmware problem:

Choose 4G instead 5G!

In the device go to: Network→Mobile→Connection

Choose the correct SIM-Card (the one you use for the internet)

Edit the “Prefered network typ” to 4G/3G auto

Save & Apply

See the attached Screenshots how to do. I know its only 4G instead of 5G, but ist a huge difference between having a little bit slower internet or no internet. Hope that will help you and hope it will help the support for solving this problem.

Screenshot_20260402-185853~2
Screenshot_20260402-185853~21080×2410 160 KB

Screenshot_20260402-185903~2
Screenshot_20260402-185903~21080×2410 172 KB

6

Greetings,

Apologies for the delayed response.

Could you please try navigating to Network → Mobile → Connection
And select NSA for the 5G Mode

image
image1123×465 53.5 KB

Please let me know if this resolves the issue.

Best Regards,
Justinas

7

I’ve tested it- IT didnt Work.

In the notification: “internal Modem is unreachable”

So right now the only workaround seems Like Switch to 4G.

The Rest is Up to you to get a new Modem Firmware running;-)

1 Like
8

Just adding that I have had exactly the same fault - works on 4G but if I set it to 5G/5G/3G auto and 5G mode to NSA, it says ‘modem unreachable’.

Screenshot 2026-04-05 at 19.39.17
Screenshot 2026-04-05 at 19.39.17944×626 21.9 KB

9

Same issue here! After updating the modem’s firmware, 5G connections can no longer be established or drop immediately. 4G connections are still possible. Release RG520NEBDCR03A05M4G appears to have a bug. Please investigate this and provide a fixed version or a way to downgrade to a stable version. Thank you.

10
1 Like