I have the exact same problem. It started on August 9th. I've jumped through hoop after hoop...running speed tests, having techs come to my home to adjust my satellite, etc etc. And no one will give me a straight answer as to what the problem is or when it will be fixed.
Welcome to the community and thank you for your post. We want to address your concerns, so please post a case number or the serial number located on the bottom/back of your modem so we can pull up your account.
To help us address your concern, please connect your computer directly to the modem and run some speed tests for us to evaluate. Please run a set of 5 speed tests 3 times over the course of a 24 hour period for us to properly evaluate your speeds. Your patience and cooperation is appreciated, and we look forward to hearing back from you.