T38G 38.70.0.125 -> 38.70.0.132 IPv6 broken

[Yealink Support]

Hi Bernhard,
You mean when you set IPV6 as Static IP Address on 38.70.0.125, everything works fine.
But when you set the same IPV6 as Static IP Address on 38.70.0.132, during the call, there's no any voice? But the account is register, and the can can also be made?
Did you try to reset to factory default?

Could you provide PCAP trace, syslog(level 6) and config.bin file from these two different firmware to us, so we can analyze?
Before you export the syslog, please set log level as 6, and reboot the phone, then click Start,and reproduce the issue, then click Stop,and export the trace, syslog, config,bin to us.
(About where to export these files, please refer to attached screenshot.)
These three files are very important for us, hope you can kindly understand.
Thanks.