Have you guys settled who's got the longest console yet? 🙂
Anyway, replay is not a video, it is a simulation based on the updates received. If the server is fully loaded, it might have problems processing the game and sending updates in time. If the simulation skips steps or receives updates late or more at once, you can imagine the result is not smooth...
Also, net might be more congested than usual. There's Black Friday in some countries, so a lot of people are shopping online. Also, it's the second wave of the pandemic and, with so many restrictions, people stay at home and eat cookies and bandwidth fulltime.