Global IPV6 DNS setting missing on machine with multiple Interface

We have Mac OS VM which has two network interfaces and both are active. In our application we need “State:/Network/Global/IPv6” to do some task but on this machine it seems to be missing, however if we disable one of the interface then the same setting seems to be available and our code works fine.

Please find the attached screenshots of working & non-working details:

Global IPV6 DNS setting missing on machine with multiple Interface
 
 
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