Hey KTM,
This post explains why streams/videos may be fine while the game disconnects. The difference is buffering (not affected by packet loss or instability) versus the game needing a constant stable connection.
Most likely the disconnect is happening somewhere between your ISP and the game servers. Without any connection data though it’s hard to say for sure. We definitely monitor the status and health of the Overwatch servers, so if there’s ever an issue that affects everyone and it’s within the Blizzard network our engineers will be on top of it. We don’t currently have anything like that going on right now though.