Missing c-ares flags on the implementation:

ref:
https://c-ares.org/ares_init_options.html

missing flags:
ARES_FLAG_EDNS
Include an EDNS pseudo-resource record (RFC 2671) in generated requests. As of v1.22, this is on by default if flags are otherwise not set.

ARES_FLAG_NO_DFLT_SVR
Do not attempt to add a default local named server if there are no other servers available. Instead, fail initialization with ARES_ENOSERVER.