Split Tunneling working for device A but not device B - Same profile used on both

[james.jackson1]

I have 2 laptops running Anyconnect Secure Mobility Client 4.7.

I am authenticated to our VPN using the same credentials on both laptops.

Laptop A has split tunneling working great. (i.e. contoso.com flows through the tunnel and resolves fine while cisco.com doesn't flow through the tunnel and resolves fine as well)

Laptop B has split tunneling working in a defunct state (i.e. contoso.com flows through the tunnel and resolves fine while cisco.com resolution fails)

Laptop A is a Latitude 3470 (manufactured in 2016) running Windows 10 with all the latest updates installed.

Laptop B is a Latitude 6420 (manufactured in 2012) running Windows 7 with all the latest updates installed.

We have an FMC/FTD environment, but any ASA advice is also welcome. As far as I can tell I have everything configured correctly, but perhaps there is some hardware constraint with Laptop B that I am unaware of.

Any insight is appreciated.

[Mohammed al Baqari]

What's your split dns config. Also, check if both laptops use the same dns
settings

[james.jackson1]

The problem is resolved on Laptop B by disabling IPv6. I can replicate this reliably.

However, toggling IPv6 on or off for Laptop A makes no difference regarding this behavior.

I am still investigating.