Decklink IP HD Optical Audio source issue

Hi, i recently bought decklink ip and testing various stuff with equipment my company has&rented. However, whenever i route Audio source into Decklink ip optical, it comes in as broken source. for instance, i can hear the music, but it comes in as music 1sec and broken static sound 1sec infinite loop or so. The Original source comes from a PC -> blackmagic teranex -> sdi to ip converter spf -> ip switch -> Panasonic Kairos switch -> antoehr PC that Decklink is installed. (and yes i do have sync generator!)
If i route sound from the PC to somewhere else, the sound is fine! it's only broken when it receive. i tried vmix,blackmagic media express,wirecast, all same issue. so i'm wondering if it's Decklink's malfunctioning or my somewhat set up issue . if anyone had similiar issue or have solution to resolve this! please!! any idea helps!! thank you!!