I'm having the same exact problem. I cant seem to stay connected for more than 5 minutes unless im in a actual match.
For example, I'm playing MW3 and during the actual play time (TDM, Sabotage, Kill confirmed etc) ill be ok. Same if i stay in the lobby while the next game starts. But as soon as I leave im disconnected. If I use netflix...disconnected...turn on espn, same thing.
I'm on a wireless router. So I unplugged for 15 seconds and pluged it back in. Reset the connection settings to default and nothing seems to be helping. What else can I do??