I'd also go with buffer issues - It's not static in any sense, so if you are doing internet searches, it won't bring back sensible results. In real terms you have gaps in the data stream. They can often be the result of a computer trying to do multiple similar processes at the same time. What are you using for the system - in terms of software and presumably some kind of host that handles connections and distribution? Searching for internet audio streaming dropouts brings up loads of responses with similar responses to here?
Clearly this is common and the suggestions always start with buffering, but also the speed of wifi connections, how the wifi stream is managed, conflicting services on the far computer - bluetooth gets a mention too. Conflicts where despite having a proper audio interface, the computer switches from the ASIO to generic high latency drivers and at the switch you get the silence or breakups. I've read where a computer had spotify running in the background and this kept hijacking the stream. I guess your remote person needs to check on their computer and see what processes are running in the background. If any are audio based - so the spotifys, the apple musics and stuff like that are prime culprits. Is the remote person using a music type computer or some low performance laptop that is trying to convert 48K, 24 bit into something else in real time to use a particular application? If your other contributors are trouble free, the the dodgy one needs some proper local input, where things can be tried and adjusted. It sounds like they're clueless and are stabbing in the dark. I doubt you can fix it unless you set up some kinf of screen sharing, and that could simply add to the computer's stress levels.
