OpenVPN problems with new firmware T26 V7

[Yealink Support]

Hello,
1. Now the issue happened in the firmware 6.70.0.130? And which firmware works well? 6.60.0.140 or other firmware version?
2. The problem is:It's ok when you make the local call with account 1, but it's not ok when you make a remote call(these two accounts are in the same OpenVPN network), both two sides do not have audio? Or only caller can not hear?
3. Could you provide the phone trace, syslog(level 6) and config.bin file both when you use V70 and V60, so we can have a reference?
Before you export the syslog, please make sure set Log Level as 6, then reboot the phone, and reproduce the issue again, then export the syslog, trace, config.bin file.
Thanks.