Occasionally my vrchat download speed (for worlds and avatars) falls to unplayable values, like less than 1mbps. It may last for a few minutes or a few hours, it's very unpredictable. Normally I have vrchat download speed of 3-5 megabytes per second.
Geographically I'm in the Far East region of Russia (near Japan), my normal Internet speed is around 100mbps.
Rebooting PC and restarting the router does not help.
Here is the video of what it looks like inside the game: https://www.youtube.com/watch?v=8x-oRRO4m6c
Other applications and web sites are not affected by this. I was able to browse the Internet at my usual speeds while I was waiting for the world (in the video above) to download.
Also I'm attaching a screenshot of the Amazon Network test that I took while the world was downloading.