Is this fix this issue too? [#2404 (comment)](https://github.com/kamailio/kamailio/issues/2404#issuecomment-661060298)
when used
bind_ipv6_link_local=0
I am not sure. The whole identification code is too convoluted for a casual analysis. If you can apply and test, we'll get the answer back.
As I said, this whole part will benefit from a rewrite. It'll be smaller, easier to analyze, more efficient and less error prone - for example, right now it's performing almost the same exchange with netlink twice and it can't handle dropped netlink messages.