I am a new customer who signed up for the blast service that is supposed to be 250mbps. I have yet to run a speed test that showed it over 100mbps. I was just on a GoTo meeting and got a slow download speed warning. I never got that once after a couple of years with 50mbps Fios service!
Start here:troubleshooting guide. If you still need help, please post your equipment details (make/model of your modem/gateway/router) and a screenshot of your signal levels and your error/event log. Thank you!