Hi,
I've been running 3.9.6BT absolutely fine, with no issues.

Upgraded to 3.9.6.1_MDM3 from the FTP site - works fine except the LTE side of things never connects.

Reverted to 3.9.6BT - all good again - I put it down to the 'international' nature of the firmware on the FTP site.

3.9.6.1BT now available so I've upgraded again...same problem, no LTE connection at all.

So I'm suspecting they've changed something that's undocumented in the release notes.

Can anybody else confirm the same issue before I revert back to 3.9.6BT again please ?

OK, gave it 40 mins - it never managed to make a successful connection to the LTE service - 'Registration Denied' was the best I managed, the LTE status just goes round and round initialising, SMS service ready, Registration denied, ad-infinitum.

Reverted back to 3.9.6BT - with no other changes whatsoever - rebooted and the LTE was connected within 30 seconds of the router becoming available again. Coincidence? I think not.

But I would like some confirmation from anybody with a similar setup.

Thanks.

I've just tested a 2862Lac on 3.9.6BT and 3.9.6.1BT to see if I could get the same problem to occur with a Virginmedia (EE MVNO) SIM card. It was able to connect on both firmware versions without issue.

Can you try again on 3.9.6.1 and set up the router to send Syslog, so that there's a full log of the connection attempt?
Setup guide: https://www.draytek.co.uk/support/guides/kb-vigor-syslog

If it's still unable to connect, I recommend contacting support as the issue might be specific to your location (cell tower/band), APN or other details.

Hi - thanks for that.

I've got syslog extracts from both firmwares connecting to LTE (or at least trying). Other than copy/pasting the whole things here is there no way to attach files - I can't see one ?
These two smaller extracts seem to show the relevant success and failure elements of the two (not sure why I'm getting all the ctrl-chars in there) :-

3.9.6BT
[4G]<5> All client IDs are ready.
[4G]<5> GNSS engine.
[4G]<5> Modem state [2], state_timer = 1
[4G]<5> WDA set data format OK.
[4G]<5> [Modem Status] ICCID: 8944125605558869282F
[4G]<5> [Modem Status] Manufacturer: DrayTek
[4G]<5> [Modem Status] IMEI: 862506040099692
[4G]<5> [Modem Status] Hardware version: 10000
[4G]<5> [Modem Status] Software version: SW25EUXGAR08A02M1G
[4G]<5> PIN code is disabled.
[4G]<5> SIM status resp.
[4G]<5> Modem state [4], state_timer = 1
[4G]<5> Set MUX_ID [0x81]
[4G]<5> LTE connects with MCC:[234] MNC:[30] for connection.
[4G]<5> No preferred LTE band. Use legal bands.
[4G]<5> Force 4G !!
[4G]<5> Preferred Band resp OK.
[4G]<5> Receive nas_serving_system_resp_ind! With state[6]
[4G]<5> Receive nas_serving_system_resp_ind! With state[6]
[4G]<5> Modem state [6], state_timer = 1
[4G]<5> Prepare SMS service.
[4G]<5> Set WMS event report OK.
[4G]<5> 3GPP SMS Service is ready.
[4G]<5> SMS service is ready now.
[4G]<5> Set NAS event report OK.
[4G]<5> Modem state [8], state_timer = 1
[4G]<5> Network is registered: LTE
[4G]<5> Modem state [9], state_timer = 1
[4G]<5> ********* LINK UP *********
[4G]<5> Draytek LTE modem initialized successfully
[4G]<5> Packet service state: Connected
[4G]<5> Necessary to reconfigure: 0
[4G]<5> Max Channel Rate: TX 50000000 bps, RX 150000000 bps
[4G]<5> Access tech : LTE. Band : E-UTRA Op Band 3.
[4G]<5> Operator Name: EE
[4G]<5> [Modem Status] IMSI: 234335505886928

3.9.6.1BT
[4G]<5> All client IDs are ready.
[4G]<5> GNSS engine.
[4G]<5> Modem state [2], state_timer = 1
[4G]<5> WDA set data format OK.
[4G]<5> [Modem Status] ICCID: 8944125605558869282F
[4G]<5> [Modem Status] Manufacturer: DrayTek
[4G]<5> [Modem Status] IMEI: 862506040099692
[4G]<5> [Modem Status] Hardware version: 10000
[4G]<5> [Modem Status] Software version: SW25EUXGAR08A02M1G
[4G]<5> PIN code is disabled.
[4G]<5> SIM status resp.
[4G]<5> Modem state [4], state_timer = 1
[4G]<5> Set MUX_ID [0x81]
[4G]<5> LTE connects with MCC:[234] MNC:[30] for connection.
[4G]<5> No preferred LTE band. Use legal bands.
[4G]<5> Force 4G !!
[4G]<5> Preferred Band resp OK.
[4G]<5> Receive nas_serving_system_resp_ind! With state[6]
[4G]<5> Modem state [6], state_timer = 1
[4G]<5> Prepare SMS service.
[4G]<5> Set WMS event report OK.
[4G]<5> 3GPP SMS Service is ready.
[4G]<5> SMS service is ready now.
[4G]<5> Set NAS event report OK.
[4G]<5> Modem state [8], state_timer = 1
[4G]<5> Modem state [8], state_timer = 2
[4G]<5> Modem state [8], state_timer = 3
[4G]<5> Modem state [8], state_timer = 4
[4G]<5> Modem state [8], state_timer = 5
[4G]<5> Modem state [8], state_timer = 6
[4G]<5> Modem state [8], state_timer = 7
[4G]<5> Receive nas_serving_system_resp_ind! With state[8]
[4G]<5> Network registration was denied by the visible LTE network.


So it seems with 3.9.6.1BT I never get past 'Modem state [8]' whereas with 3.9.6 it works just fine.

Any thoughts before I go to support with it ?

Thanks again.
Ian

Try turning off Force 4G. I was testing with a factory default router and while I'm not asking you to do that, there aren't many more settings to change really than APN, band preference and force 2G/3G/4G.