Cisco AnyConnect VPN keeps disconnecting

[Davefromdowntown]

Let me start by saying that I have no idea if this is the right place to post; if not if someone can kindly direct me to where to do so, I would be most grateful.

My wife has been working from home during the pandemic, and with our previous home network setup (Arris S33 Cable Modem, and ASUS RT-AC88U router) everything has been working great.
I recently decided to upgrade equipment, and got an all in one (gateway) device, Arris G36. Ever since doing this, her VPN (Cisco AnyConnect) keeps disconnecting from the VPN every 3-5- minutes which makes it impossible for her to work since she takes phone calls.

I've spent four hours with Arris on the phone and tried all the things they've suggested (adding the IP of the computer to DMZ, disabling firewall, and a few other things, port forwarding at least based on info I could find) - none of this helps, and it still disconnects every 3-5 minutes like clock work.
Admittedly I haven't the slightest idea of what it could be, or how to fix it and was hoping maybe someone had a suggestion to nudge me in the right direction.

Her computer gets internet connectivity just fine -- once she connects to the VPN however that only retains connection for the 3-5 minute window then reconnects. She has a pretty locked down computer and can't make any changes since it's a company computer, so I'm not sure if there's something maybe I can suggest that her IT guys (who don't seem very competent to begin with) could try?

I am hopeful someone can guide me in the right direction to fix this.

Thanks so much.

[balaji.bandi]

as per the information this more to do with Arris G36 Broadband router, not related any connected (since you mentioned it was working)

worth looking some settings as mentionedbelow thread see if that can help you :

https://community.cisco.com/t5/vpn/anyconnect-vpn-session-disconnect-and-reconnect/td-p/2474657

[Davefromdowntown]

Thanks, unfortunately I'm sort of a dunce when it comes to this sort of thing so most of the information you linked is foreign to me.  I did manage to at least get a look at the logs that got created by running DART (zero clue what most of that means), and my wife's IT department seems unwilling to even try and assist so I guess it's back to my old setup I go.

I worked with Arris again for a couple of hours, tried opening whatever ports posts that I found stated needed to be open, and also put the IP of her computer in the DMZ, none of this helped, still disconnects from the VPN every 3-5 minutes and if she's on a call that call drops and all incoming calls after are silence.

I imagine most of the stuff you linked needs to be checked on her employers side, and they just don't seem to either have an idea or don't want to fiddle with it -- hopefully my current setup sticks for the interim. 

Edit: I just read the information in this link from the link you posted and am wondering what the chances of it fixing the issue are; I just need to get someone from her IT team to login to her computer with admin rights I assume, and apply the changes to her firewall?

http://blog.idmware.com/2019/12/client-side-fix-cisco-anyconnect.html

[balaji.bandi]

I can understand and good luck !