Motorola SB6183 and slow speed.

Hello I am on the preferred tier of 50Mbps download but it only seems to reach about half the download speed. Replaced the modem a week ago and there was a slight improvement to 30Mbps. Contacted chat who sent something to my modem and disconnected the chat session but the speed checks are still at 30Mbps. The signal levels look within reason. It feels like we are restricted to an older tier level or something. Is there any other steps we can do? Thanks.