Setting up 4G backup on FritzBox 7530

FritzBox 7530 4G Failover to three network not registering.

Hi I have
Fritzbox 7530 with Zen Internet - Fibre
Huawei E3372h-320 USB Dongle
Three Preloaded SIM 24G/2 years

The dongle and SIM work first time plugged into Linux Mint laptop.
The dongle software reports APN = 3internet

When I try the dongle in the FritzBox it fails to register. I see the following:

- The PIN was accepted
- Registration failed

For the APN details -
when I plug the dongle directly into the laptop the Huawei web interface already displays a 3 UK profile.
(presumably loaded from the SIM somehow?)
This only contains APN=3internet , blank user/pwd.

The FritzBox asks for APN details: (does this then ignore the profiles configured on the USB and SIM?)
I've tried:
Access Point: 3internet (also tried three.co.uk)
Access Number: <blank> (alos tried *99# and *99***1#
User/Pwd = <blank>

But it always fails to register. Any advice appreciated!

Edited by deleted (Fri 17-Jul-20 22:54:23)

Hmm looks like this might be related to HiLink.

So either I get a non-hilink USB stick or I flash it?

Why don't you try to contact AVM support. A Zen supplied router does not have any ZEN specific firmware.

https://en.avm.de/service/support-request/your-suppo...

AVM Fritz OS 7.25 (March 2021) now works with the Hi-Link software in the Huwei Dongle.

PS I bought the router from ebay (Zen provided an older model at the time) and my only mention of Zen for completeness - I wasn't expecting them to help