But this only matters either if you don't have enough bandwidth to compensate and a buffer, or for whatever reason can't buffer much (e.g. it's live and two-way)
Yeah hence I mention the WAN. Generally some link along your WAN route is oversaturated, on a shitty ISP it's probably the link to your local ISP itself. I presumed audiophile switches would be popular for real-time streaming solutions, but I still don't understand the appeal.