laptop connected to wifi but no internet when firewall is off

afternoon friends,

I really need help with this laptop that i am struggling with for a few days now. here is the issue: my client has his own firewall, so he doesnt use windows firewall, and his firewall automatically shuts down windows firewall. so he called complaining that he has no internet although the laptop connects ormally to wifi and cable.

after a few analisys, we realized that, once the laptop is removed from the client's domain, the internet comes back on, with windows firewall turned on. but once we turn off windows firewall, even though the laptop is not on my client's domain, therefore not using the client's firewall, the internet goes off. the thing is, the company's policiy forces them to use their own forewall instead of window's own firewall...so, unless there is a way to make fix the laptop to work with windwos firewall turned off, the laptop will not browse to the internet.

so please, ideas, any you have.

it a dell latitude 5580 with windows 10 professional 64bit

i5, 7th Gen.