Hi Fai,
I think this issue is a combination of things: the Kali cannot stay in sync with the streaming and that’s why it does not stay delayed constantly at 0. seconds. Probably the streaming is dropping audio packets to stay in sync.
I really don’t know how to help you on this one… The best thing you can do is to try Kodi settings to get the most stable streaming possible…
The BOSS will not have this issue since its not a reclocker