NUC running OPNSense 25.1.11 drops connections when using VPN or d/loading files

[Old_Rager]

Hey Guys,

This thread is a continuation of this thread from about 4-5 months ago (https://forum.opnsense.org/index.php?topic=44356.msg231128#msg231128).

My setup is as follows:
- ISP connection is 750Mbps down and 100Mbps up.
- My ISP has given me an Adtran 422G GFast NTU to connect to the internet.
- I have a DreamQuest Pro N5105 NUC with 2 x 1 Gbps ethernet ports that utilises an Intel 3165NGw network interface card (NIC) as a bare metal OPNsense device running version 25.7.2 before providing access to the rest of my home network.  The NUC that runs OPNSense runs all firewall, DHCP, and DNS activities for my home network.

What happens is that generally (not all the time) whenever I connect to a VPN or download files, the connection to the internet drops.  The unfortunate thing is it generally drops a few times a day when my wife works from home which is fast becoming a problem for us.  I have noticed that I can still access the OPNSense system on the NUC but have no idea what I'd be doing in this regard.  Some people have said that I need to have a look at certain access logs to see what is going on, but seriously, I'd need very specific instructions on how to do this as technology is really starting get beyond me these days even taking into account that I was once an MSCP in MS Windows 3.1... 🤣

In the previous post, someone suggested that I ascertain which NIC my NUC was using as I might need a dedicated NIC driver to alleviate the problem.  I notice that there is a post RE: the Intel 3165NGw NIC on the OPNSense forums, but this was ~8 years ago now (https://forum.opnsense.org/index.php?topic=6452.0).  Additionally, this post made the following statement but am not sure what in fact it actually means - "But I think that only client mode will be supported by the driver! So you can't use this wifi card to offer an AP on OPNsense."

If anybody could help me get to the bottom of what is going on here, it would be very much appreciated indeed.  Why this keeps happening to my setup I don't know, but I hear of others using OPNSense having no problems whatsoever...  😭😞