[Freeswitch-users] Two endpoints with same extension but only one is ringing

Hi, I have running Freeswitch (Version 1.6.19~64bit) and 2 endpoints registered with the same extension in the same network First: Grandstream GXV3370 (Version 1.0.1.12) Second: Android GS Wave App (Version 1.0.3.10) Sometimes it works fine. But most time only one device is ringing when calling the extension. The logfile is fine - I can see invites to both devices. Registration-Status is fine. Where do I start to search for the problem? Local WLAN-Router? Best regards, Thorsten