You asked this by email too. Please don't ask the same question in multiple places. Forum is the best place to ask (so other people can hopefully search and find the answer).
Also, we answered this by email too.
Short answer: the customer configured their docker container incorrectly. Have them make a container with at least one “real emulated” network adapter.
No, we will not be describing how to do this. It's beyond the scope of our support. Yes, this is doable.
My advice: don't use docker. It's a VM without the slim-security benefits (and speed benefits) of VMs.
But people will do what they want. Yes, this is solvable, but it's a problem that's left to the customer.