Issue with T-mobile Home 5G and Cisco AnyConnect

Oups wrote:

Hola,

When I try to connect my vpn Cisco Anyconnect with my box Home 5G, I have this message:

"The VPN was terminated due to a loss of communication with the secure gateway. A new connection is necessary, which requires re-authentification."

I tried to Allow local (LAN) access when using VPN (if configured) but it did not work.

I have no idea what to do. I work for a big foreigner entity and it is very difficult to have answers.

You did the checkbox, so maybe changing the MTU might help.

My tech for the company I work with states they may be blocking ports and outdated firmware and T-Mobile internet stated they do not block ports and firmware is sent automatically. 
but why of all sudden is this happening 

I connect to multiple customers with cisco connect.  Once I changed the mtu to 1420 I had no problems with my tmobile internet connection.  I even have a user that uses saml in cisco anyconnect and it works just fine.  I would check with your company and see if they are blocking IP addresses.

Do you change the MTU on Cisco any connect or the T-Mobile internet settings? 
 

I was told by my company it dept that it’s not a steady connection and that T-Mobile may be blocking ports and old firmware but I’ve called T-Mobile internet support & they stated they are not blocking any ports and send firmware update’s automatically