I can vouch for this. So, I'm not the only one. What's weird is that the silence is annoying the heck out of me for simply not being there as it should. I guess I just hate inconsistency as it pops in only when it wants to.
I'm kind of used to it disappearing every so often. There was a bug in the safehouses that did the same thing when you loaded into them.
Hi Everyone, We're looking into this right now. If the zipline visual effect dissapears, the sound will not play. That's because the sound is tied to the visual. We will get this figured out as soon as possible. Thanks for your patience and thanks for bringing it to our attention on the forums. Best, DC_Homeslice
Hi Everyone, Quick Update. We have pinpointed the reason why the zipline FX was not playing and we should have a fix for it soon. Best, DC_Homeslice