Recently signed up for new contract, now only have 1 HD stream and 3 SD streams

My promotion from last year just ran out recently, so I signed up for a new one.  They said nothing would change, other than an upgrade to U300 from U200 and a slightly higher bill.  I've noticed my internet has been spotty lately and now when I watch TV while someone is watching downstairs, it says there are too many HD services in use.  I don't get why my service was downgraded!