Video is slow, audio stops every second while internet speed is 15 Mb/s

My download speed is 15Mb/s, upload speed is 15Mb/s too. I'm downloading from torrents with that speed. But video in Adobe connect is slow and audio stops every second. Adobe test tell me that I use modem connection. I'm 100% sure that I'm not downloading anything whe I use Adobe connect. Tried different browsers, computers (internet provider is the same).

When I try to download smth from browser, the speed is very low too.