Original Audio Delay

When sharing the original stereo computer sound, my collaborators start getting a huge amount of delay on that (up to 5 seconds!). On the other hand, both the screen and camera video and microphone audio have a decent amount of latency (<500ms). 

Why does the computer audio present this delay and how can I reduce it?

My connection is FTTH with over 100Mbps (speedtest) in download and upload so I guess it shouldn't be the problem.

Thanks