I have a 4G simcard, and a Huawei USB access point. If the sim card is in the Huawei within a minute its found a 4G signal and I can connect my laptop to it either via USB or Wifi.
If I put the same simcard in my Draytek Vigor 2865 LAC it takes ages to find the signal, I have the LTE antennas. On the dashboard the LTE bit is red, keeps saying searching, and then randomly it will go green.
I have tried with my phone sim card that has 4G data, and again the same thing.
I have put the data sim card in my phone to test it, and internet works on it.
I have disabled all other WAN so that the only ones showing were LTE and USB
I then disabled USB WAN, and still it takes ages to find the signal and go green.
Does anyone know why?

I've got an ongoing issue at the moment and a support ticket logged with the Vigor 2865 Lac.

The LTE seemingly goes into a searching network mode disabling the use of SMS, the LTE is in failover mode and falls over correctly though.

My problems seemed to start and are present in any firmware from 4.3.2, firmware 4.3.1.1 works fine however with no problems.

You don't mention what firmware you're using but if it's any use I'm using a UK 'EE' SIM card. Maybe the issues are related somehow or maybe not but there definitely seems to be a few odd problems with the LTE on this model since firmware 4.3.1.1.

It might be worth logging a support ticket with Draytek.

Its a data sim card that work gave me.
Its white in colour, and I believe it was EE. Strange thing is that when using the internet on it, and my location, it comes up with Orange France, and all ads on youtube are in French, and it thinks I am in Paris.
On the Huawei dongle same thing happened, but within turning it on, in a few moments I was connected to the net.
I just had a look at it now and got:
Operational
Bridge mode
Disabled
Access Tech
LTE
Band
E-UTRA Op Band 20
Operator
voda UK
Signal
RSRP: -92 dBm (Good)
RSSI: -62 dBm (Excellent)

Model Name : Vigor2865Lac
Firmware Version : 4.2.4_BT
Build Date/Time : Mar 18 2021 17:52:26

mda99das wrote:
It's white in colour, and I believe it was EE. Strange thing is that when using the internet on it, and my location, it comes up with Orange France, and all ads on youtube are in French, and it thinks I am in Paris.

So is this actually a 'roaming' issue?

It's a while since I've been out of the country, but when abroad, I remember my phone occasionally connecting to a network, with whom my provider had no commercial agreement (so it didn't work). On a phone, you can normally override the automatic selection - I'm not sure how or if, that applies to a 2865...

no don't think it is, as with my vodafone sim card same thing happens, takes ages.
Tried my wife's 3 sim card and same thing
Put any sim in the Huawei mobile dongle and less than a minute it has connected.

Another way round, can you just plug the Huawei in via USB?