i have tested the sample config from:
https://kb.asipto.com/kamailio:kamailio-mixed-ipv4-ipv6

i found that i can register with v4 to kamailio and to the provider

if i user ipv6 to kamailio and ipv4 to provider i canĀ“t register.

the packet from the provider contain a via entry which is missing from kamailio to my phone.

Someone have a solution ?